diff --git a/include/xlnt/cell/cell.hpp b/include/xlnt/cell/cell.hpp
index a14544ec..a0c3e9c5 100644
--- a/include/xlnt/cell/cell.hpp
+++ b/include/xlnt/cell/cell.hpp
@@ -33,7 +33,9 @@
 namespace xlnt {
     
 class cell_reference;
+class comment;
 class relationship;
+class value;
 class worksheet;
 
 struct date;
@@ -43,22 +45,7 @@ struct timedelta;
 
 namespace detail {    
 struct cell_impl;
-struct comment_impl;
 } // namespace detail
-    
-class comment
-{
-public:
-    comment(const std::string &text, const std::string &author);
-    ~comment();
-    std::string get_text() const;
-    std::string get_author() const;
-    
-private:
-    friend class cell;
-    comment(detail::comment_impl *d);
-    detail::comment_impl *d_;
-};
 
 /// <summary>
 /// Describes cell associated properties.
@@ -72,15 +59,6 @@ private:
 class cell
 {
 public:
-    enum class type
-    {
-        null,
-        numeric,
-        string,
-        boolean,
-        error
-    };
-
     static const std::unordered_map<std::string, int> ErrorCodes;
     
     static std::string check_string(const std::string &value);
@@ -88,24 +66,14 @@ public:
     static std::string check_error(const std::string &value);
     
     cell();
-    cell(worksheet ws, const cell_reference &reference, const std::string &initial_value = std::string());
-    
-    std::string get_internal_value_string() const;
-    long double get_internal_value_numeric() const;
+    cell(worksheet ws, const cell_reference &reference);
+    cell(worksheet ws, const cell_reference &reference, const value &initial_value);
     
     std::string get_column() const;
     row_t get_row() const;
     
     std::string to_string() const;   
     
-    void set_explicit_value(const std::string &value, type data_type);
-    void set_explicit_value(int value, type data_type);
-    void set_explicit_value(double value, type data_type);
-    void set_explicit_value(const date &value, type data_type);
-    void set_explicit_value(const time &value, type data_type);
-    void set_explicit_value(const datetime &value, type data_type);
-    type data_type_for_value(const std::string &value);
-    
     bool is_merged() const;
     void set_merged(bool merged);
     
@@ -116,11 +84,12 @@ public:
     void set_number_format(const std::string &format_code);
     
     bool has_style() const;
-    
     style &get_style();
     const style &get_style() const;
-    
-    type get_data_type() const;
+
+    std::pair<int, int> get_anchor() const;
+
+    bool garbage_collectible() const;
     
     cell_reference get_reference() const;
     
@@ -139,49 +108,33 @@ public:
 
     std::string get_error() const;
     void set_error(const std::string &error);
-
-    void set_null();
     
     cell offset(row_t row, column_t column);
     
     worksheet get_parent();
+    const worksheet get_parent() const;
+
+    value &get_value();
+    const value &get_value() const;
+    void set_value(bool b);
+    void set_value(int i);
+    void set_value(double d);
+    void set_value(long double d);
+    void set_value(long long int i);
+    void set_value(const date &d);
+    void set_value(const datetime &d);
+    void set_value(const time &t);
+    void set_value(const timedelta &t);
+    void set_value(const char *s);
+    void set_value(const std::string &s);
+    void set_value(const value &v);
     
     cell &operator=(const cell &rhs);
-    cell &operator=(bool value);
-    cell &operator=(int value);
-    cell &operator=(double value);
-    cell &operator=(long int value);
-    cell &operator=(long long value);
-    cell &operator=(long double value);
-    cell &operator=(const std::string &value);
-    cell &operator=(const char *value);
-    cell &operator=(const date &value);
-    cell &operator=(const time &value);
-    cell &operator=(const datetime &value);
-    cell &operator=(const timedelta &value);
     
     bool operator==(const cell &comparand) const;
     bool operator==(std::nullptr_t) const;
-    bool operator==(bool comparand) const;
-    bool operator==(int comparand) const;
-    bool operator==(double comparand) const;
-    bool operator==(const std::string &comparand) const;
-    bool operator==(const char *comparand) const;
-    bool operator==(const date &comparand) const;
-    bool operator==(const time &comparand) const;
-    bool operator==(const datetime &comparand) const;
-    bool operator==(const timedelta &comparand) const;
 
     friend bool operator==(std::nullptr_t, const cell &cell);
-    friend bool operator==(bool comparand, const cell &cell);
-    friend bool operator==(int comparand, const cell &cell);
-    friend bool operator==(double comparand, const cell &cell);
-    friend bool operator==(const std::string &comparand, const cell &cell);
-    friend bool operator==(const char *comparand, const cell &cell);
-    friend bool operator==(const date &comparand, const cell &cell);
-    friend bool operator==(const time &comparand, const cell &cell);
-    friend bool operator==(const datetime &comparand, const cell &cell);
-
     friend bool operator<(cell left, cell right);
     
 private:
diff --git a/include/xlnt/cell/comment.hpp b/include/xlnt/cell/comment.hpp
new file mode 100644
index 00000000..b40b7b69
--- /dev/null
+++ b/include/xlnt/cell/comment.hpp
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <string>
+
+namespace xlnt {
+namespace detail {
+struct cell_impl;
+struct comment_impl;
+} // namespace detail
+
+class comment
+{
+public:
+    comment(const std::string &text, const std::string &author);
+    ~comment();
+    std::string get_text() const;
+    std::string get_author() const;
+
+private:
+    friend class cell;
+    comment(detail::comment_impl *d);
+    detail::comment_impl *d_;
+};
+
+} // namespace xlnt
diff --git a/include/xlnt/cell/value.hpp b/include/xlnt/cell/value.hpp
new file mode 100644
index 00000000..ec313433
--- /dev/null
+++ b/include/xlnt/cell/value.hpp
@@ -0,0 +1,108 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+namespace xlnt {
+
+struct date;
+struct datetime;
+struct time;
+struct timedelta;
+
+class value
+{
+public:
+    enum class type
+    {
+        null,
+        numeric,
+        string,
+        boolean,
+        error
+    };
+
+    static value null();
+    static value error(const std::string &error_string);
+
+    value();
+    value(value &&v);
+    value(bool b);
+    value(int8_t i);
+    value(int16_t i);
+    value(int32_t i);
+    value(int64_t i);
+    value(uint8_t i);
+    value(uint16_t i);
+    value(uint32_t i);
+    value(uint64_t i);
+    value(float f);
+    value(double d);
+    value(long double d);
+    value(const char *s);
+    value(const std::string &s);
+    value(const date &d);
+    value(const datetime &d);
+    value(const time &t);
+    value(const timedelta &t);
+
+    template<typename T>
+    T get() const;
+
+    template<typename T>
+    T as() const;
+
+    type get_type() const;
+    bool is(type t) const;
+
+    bool is_integral() const;
+
+    std::string to_string() const;    
+
+    value &operator=(value other);
+
+    value &operator=(bool b);
+    value &operator=(int8_t i);
+    value &operator=(int16_t i);
+    value &operator=(int32_t i);
+    value &operator=(int64_t i);
+    value &operator=(uint8_t i);
+    value &operator=(uint16_t i);
+    value &operator=(uint32_t i);
+    value &operator=(uint64_t i);
+    value &operator=(const char *s);
+    value &operator=(const std::string &s);
+    value &operator=(const date &d);
+    value &operator=(const datetime &d);
+    value &operator=(const time &t);
+    value &operator=(const timedelta &t);
+
+    bool operator==(const value &comparand) const;
+    bool operator==(bool comparand) const;
+    bool operator==(int comparand) const;
+    bool operator==(double comparand) const;
+    bool operator==(const std::string &comparand) const;
+    bool operator==(const char *comparand) const;
+    bool operator==(const date &comparand) const;
+    bool operator==(const time &comparand) const;
+    bool operator==(const datetime &comparand) const;
+    bool operator==(const timedelta &comparand) const;
+
+    friend bool operator==(bool comparand, const value &v);
+    friend bool operator==(int comparand, const value &v);
+    friend bool operator==(double comparand, const value &v);
+    friend bool operator==(const std::string &comparand, const value &v);
+    friend bool operator==(const char *comparand, const value &v);
+    friend bool operator==(const date &comparand, const value &v);
+    friend bool operator==(const time &comparand, const value &v);
+    friend bool operator==(const datetime &comparand, const value &v);
+
+    friend void swap(value &left, value &right);
+
+private:
+    type type_;
+    std::string string_value_;
+    long double numeric_value_;
+};
+
+} // namespace xlnt
diff --git a/include/xlnt/common/datetime.hpp b/include/xlnt/common/datetime.hpp
index fc852eb5..08467743 100644
--- a/include/xlnt/common/datetime.hpp
+++ b/include/xlnt/common/datetime.hpp
@@ -55,7 +55,7 @@ struct time
     static time now();
     static time from_number(long double number);
 
-    time(int hour = 0, int minute = 0, int second = 0, int microsecond = 0)
+    explicit time(int hour = 0, int minute = 0, int second = 0, int microsecond = 0)
         : hour(hour), minute(minute), second(second), microsecond(microsecond)
     {
     }
diff --git a/include/xlnt/worksheet/worksheet.hpp b/include/xlnt/worksheet/worksheet.hpp
index bc3d3d59..139a91d2 100644
--- a/include/xlnt/worksheet/worksheet.hpp
+++ b/include/xlnt/worksheet/worksheet.hpp
@@ -156,7 +156,7 @@ struct page_setup
     
 public:
     page_setup() : default_(true), break_(page_break::none), sheet_state_(sheet_state::visible), paper_size_(paper_size::letter),
-    orientation_(orientation::portrait), fit_to_page_(false), fit_to_height_(false), fit_to_width_(false) {}
+    orientation_(orientation::portrait), fit_to_page_(false), fit_to_height_(false), fit_to_width_(false), horizontal_centered_(false), vertical_centered_(false), scale_(1) {}
     bool is_default() const { return default_; }
     page_break get_break() const { return break_; }
     void set_break(page_break b) { default_ = false; break_ = b; }
@@ -172,6 +172,12 @@ public:
     void set_fit_to_height(bool fit_to_height) { default_ = false; fit_to_height_ = fit_to_height; }
     bool fit_to_width() const { return fit_to_width_; }
     void set_fit_to_width(bool fit_to_width) { default_ = false; fit_to_width_ = fit_to_width; }
+    void set_horizontal_centered(bool horizontal_centered) { default_ = false; horizontal_centered_ = horizontal_centered; }
+    bool get_horizontal_centered() const { return horizontal_centered_; }
+    void set_vertical_centered(bool vertical_centered) { default_ = false; vertical_centered_ = vertical_centered; }
+    bool get_vertical_centered() const { return vertical_centered_; }
+    void set_scale(double scale) { default_ = false; scale_ = scale; }
+    double get_scale() const { return scale_; }
     
 private:
     bool default_;
@@ -182,6 +188,9 @@ private:
     bool fit_to_page_;
     bool fit_to_height_;
     bool fit_to_width_;
+    bool horizontal_centered_;
+    bool vertical_centered_;
+    double scale_;
 };
 
 struct margins
@@ -248,6 +257,12 @@ public:
     range columns() const;
     std::list<cell> get_cell_collection();
 
+    cell_reference get_point_pos(int left, int top) const;
+    cell_reference get_point_pos(const std::pair<int, int> &point) const;
+
+    const std::unordered_map<column_t, double> &get_column_dimensions() const;
+    const std::unordered_map<row_t, double> &get_row_dimensions() const;
+
     // named range
     void create_named_range(const std::string &name, const range_reference &reference);
     bool has_named_range(const std::string &name);
diff --git a/include/xlnt/xlnt.hpp b/include/xlnt/xlnt.hpp
index 01b1df1c..2ded836c 100644
--- a/include/xlnt/xlnt.hpp
+++ b/include/xlnt/xlnt.hpp
@@ -48,3 +48,5 @@ const std::string download_url = "https://github.com/tfussell/xlnt/archive/maste
 #include "common/string_table.hpp"
 #include "common/zip_file.hpp"
 #include "workbook/document_properties.hpp"
+#include "cell/value.hpp"
+#include "cell/comment.hpp"
diff --git a/source/cell.cpp b/source/cell.cpp
index 5e85fd8a..ccb45ebb 100644
--- a/source/cell.cpp
+++ b/source/cell.cpp
@@ -4,6 +4,8 @@
 
 #include "cell/cell.hpp"
 #include "cell/cell_reference.hpp"
+#include "cell/comment.hpp"
+#include "cell/value.hpp"
 #include "common/datetime.hpp"
 #include "common/relationship.hpp"
 #include "worksheet/worksheet.hpp"
@@ -12,48 +14,101 @@
 #include "workbook/workbook.hpp"
 #include "workbook/document_properties.hpp"
 
+namespace {
+
+std::vector<std::string> split_string(const std::string &string, char delim = ' ')
+{
+    std::stringstream ss(string);
+    std::string part;
+    std::vector<std::string> parts;
+    while(std::getline(ss, part, delim))
+    {
+        parts.push_back(part);
+    }
+    return parts;
+}
+
+xlnt::value::type data_type_for_value(const std::string &value)
+{
+    if(value.empty())
+    {
+        return xlnt::value::type::null;
+    }
+
+    if(value[0] == '0')
+    {
+        if(value.length() > 1)
+        {
+            if(value[1] == '.' || (value.length() > 2 && (value[1] == 'e' || value[1] == 'E')))
+            {
+                auto first_non_number = std::find_if(value.begin() + 2, value.end(),
+                    [](char c) { return !std::isdigit(c, std::locale::classic()); });
+                if(first_non_number == value.end())
+                {
+                    return xlnt::value::type::numeric;
+                }
+            }
+            auto split = split_string(value, ':');
+            if(split.size() == 2 || split.size() == 3)
+            {
+                for(auto part : split)
+                {
+                    try
+                    {
+                        std::stoi(part);
+                    }
+                    catch(std::invalid_argument)
+                    {
+                        return xlnt::value::type::string;
+                    }
+                }
+                return xlnt::value::type::numeric;
+            }
+            else
+            {
+                return xlnt::value::type::string;
+            }
+        }
+        return xlnt::value::type::numeric;
+    }
+    else if(value[0] == '#')
+    {
+        return xlnt::value::type::error;
+    }
+    else
+    {
+        char *p;
+        strtod(value.c_str(), &p);
+        if(*p != 0)
+        {
+            static const std::vector<std::string> possible_booleans = {"TRUE", "true", "FALSE", "false"};
+            if(std::find(possible_booleans.begin(), possible_booleans.end(), value) != possible_booleans.end())
+            {
+                return xlnt::value::type::boolean;
+            }
+            if(value.back() == '%')
+            {
+                strtod(value.substr(0, value.length() - 1).c_str(), &p);
+                if(*p == 0)
+                {
+                    return xlnt::value::type::numeric;
+                }
+            }
+            return xlnt::value::type::string;
+        }
+        else
+        {
+            return xlnt::value::type::numeric;
+        }
+    }
+}
+
+} // namespace
+
 namespace xlnt {
     
 const xlnt::color xlnt::color::black(0);
 const xlnt::color xlnt::color::white(1);
-
-detail::comment_impl::comment_impl() : parent_worksheet_(nullptr)
-{
-}
-    
-detail::comment_impl::comment_impl(detail::worksheet_impl *ws, const cell_reference &ref, const std::string &text, const std::string &author) : parent_worksheet_(ws), parent_cell_(ref), text_(text), author_(author)
-{
-    
-}
-    
-comment::comment(const std::string &text, const std::string &author) : d_(new detail::comment_impl())
-{
-    d_->text_ = text;
-    d_->author_ = author;
-}
-
-comment::comment(detail::comment_impl *d) : d_(d)
-{
-}
-
-comment::~comment()
-{
-    if(d_->parent_worksheet_ == nullptr)
-    {
-        delete d_;
-        d_ = nullptr;
-    }
-}
-
-std::string comment::get_author() const
-{
-    return d_->author_;
-}
-
-std::string comment::get_text() const
-{
-    return d_->text_;
-}
     
 const std::unordered_map<std::string, int> cell::ErrorCodes =
 {
@@ -73,203 +128,148 @@ cell::cell() : d_(nullptr)
 cell::cell(detail::cell_impl *d) : d_(d)
 {
 }
-    
-cell::cell(worksheet worksheet, const cell_reference &reference, const std::string &initial_value) : d_(nullptr)
+
+cell::cell(worksheet worksheet, const cell_reference &reference) : d_(nullptr)
 {
     cell self = worksheet.get_cell(reference);
     d_ = self.d_;
+}
+    
+cell::cell(worksheet worksheet, const cell_reference &reference, const value &initial_value) : cell(worksheet, reference)
+{
+    set_value(initial_value);
+}
 
-    if(initial_value != "")
+bool cell::garbage_collectible() const
+{
+    return !(get_value().get_type() != value::type::null || is_merged() || has_comment() || has_formula());
+}
+
+value &cell::get_value()
+{
+    return d_->value_;
+}
+
+const value &cell::get_value() const
+{
+    return d_->value_;
+}
+
+void cell::set_value(const value &v)
+{
+    d_->value_ = v;
+}
+
+void cell::set_value(const std::string &s)
+{
+    if(!get_parent().get_parent().get_guess_types())
     {
-        *this = initial_value;
+        d_->is_date_ = false;
+        d_->value_ = value(s);
+    }
+    else
+    {
+        d_->is_date_ = false;
+
+        switch(data_type_for_value(s))
+        {
+        case value::type::numeric:
+            if(s.find(':') != std::string::npos)
+            {
+                d_->is_date_ = true;
+                d_->value_ = value(time(s).to_number());
+            }
+            else if(s.back() == '%')
+            {
+                d_->value_ = value(std::stod(s.substr(0, s.length() - 1)) / 100);
+                get_style().get_number_format().set_format_code(xlnt::number_format::format::percentage);
+            }
+            else
+            {
+                d_->value_ = value(std::stod(s));
+            }
+            break;
+        case value::type::boolean:
+            d_->value_ = value(s == "TRUE" || s == "true");
+            break;
+        case value::type::error:
+            d_->value_ = value(s);
+            break;
+        case value::type::string:
+            d_->value_ = value(s);
+            break;
+        case value::type::null:
+            d_->value_ = value::null();
+            break;
+        default: throw data_type_exception();
+        }
     }
 }
 
-std::string cell::get_internal_value_string() const
+void cell::set_value(const char *s)
 {
-    switch(d_->type_)
-    {
-    case type::string:
-        return d_->string_value;
-    case type::error:
-        return d_->string_value;
-    default:
-        throw std::runtime_error("bad enum");
-    }
+    set_value(std::string(s));
+}
+
+void cell::set_value(bool b)
+{
+    d_->value_ = value(b);
+}
+
+void cell::set_value(int i)
+{
+    d_->value_ = value(i);
+}
+
+void cell::set_value(long long int i)
+{
+    d_->value_ = value(i);
+}
+
+void cell::set_value(double d)
+{
+    d_->value_ = value(d);
+}
+
+void cell::set_value(const date &d)
+{
+    d_->is_date_ = true;
+    auto base_date = get_parent().get_parent().get_properties().excel_base_date;
+    set_value(d.to_number(base_date));
+}
+
+void cell::set_value(const datetime &d)
+{
+    d_->is_date_ = true;
+    auto base_date = get_parent().get_parent().get_properties().excel_base_date;
+    set_value(d.to_number(base_date));
+}
+
+void cell::set_value(const time &t)
+{
+    d_->is_date_ = true;
+    set_value(t.to_number());
+}
+
+void cell::set_value(const timedelta &t)
+{
+    d_->is_date_ = true;
+    set_value(t.to_number());
 }
 
 bool cell::has_style() const
 {
     return d_->style_ != nullptr;
 }
-    
-long double cell::get_internal_value_numeric() const
-{
-    switch(d_->type_)
-    {
-    case type::numeric:
-        return d_->numeric_value;
-    case type::boolean:
-        return d_->numeric_value == 0 ? 0 : 1;
-    default:
-        throw std::runtime_error("bad enum");
-    }
-}
 
 row_t cell::get_row() const
 {
-    return d_->row + 1;
+    return d_->row_ + 1;
 }
 
 std::string cell::get_column() const
 {
-    return cell_reference::column_string_from_index(d_->column + 1);
-}
-
-std::vector<std::string> split_string(const std::string &string, char delim = ' ')
-{
-    std::stringstream ss(string);
-    std::string part;
-    std::vector<std::string> parts;
-    while(std::getline(ss, part, delim))
-    {
-        parts.push_back(part);
-    }
-    return parts;
-}
-
-cell::type cell::data_type_for_value(const std::string &value)
-{
-    if(value.empty())
-    {
-        return type::null;
-    }
-    
-    if(value[0] == '0')
-    {
-        if(value.length() > 1)
-        {
-            if(value[1] == '.' || (value.length() > 2 && (value[1] == 'e' || value[1] == 'E')))
-            {
-                auto first_non_number = std::find_if(value.begin() + 2, value.end(),
-                                                     [](char c) { return !std::isdigit(c, std::locale::classic()); });
-                if(first_non_number == value.end())
-                {
-                    return type::numeric;
-                }
-            }
-            auto split = split_string(value, ':');
-            if(split.size() == 2 || split.size() == 3)
-            {
-                for(auto part : split)
-                {
-                    try
-                    {
-                        std::stoi(part);
-                    }
-                    catch(std::invalid_argument)
-                    {
-                        return type::string;
-                    }
-                }
-                return type::numeric;
-            }
-            else
-            {
-                return type::string;
-            }
-        }
-        return type::numeric;
-    }
-    else if(value[0] == '#')
-    {
-        return type::error;
-    }
-    else
-    {
-        char *p;
-        strtod(value.c_str(), &p);
-        if(*p != 0)
-        {
-            static const std::vector<std::string> possible_booleans = {"TRUE", "true", "FALSE", "false"};
-            if(std::find(possible_booleans.begin(), possible_booleans.end(), value) != possible_booleans.end())
-            {
-                return type::boolean;
-            }
-            if(value.back() == '%')
-            {
-                strtod(value.substr(0, value.length() - 1).c_str(), &p);
-                if(*p == 0)
-                {
-                    return type::numeric;
-                }
-            }
-            return type::string;
-        }
-        else
-        {
-            return type::numeric;
-        }
-    }
-}
-
-void cell::set_explicit_value(const std::string &value, type data_type)
-{
-    d_->type_ = data_type;
-
-    switch(data_type)
-    {
-        /*
-    case type::null:
-        if(value != "")
-        {
-            throw data_type_exception();
-        }
-        return;
-    case type::error: d_->string_value = value; return;
-    case type::boolean:
-        d_->numeric_value = value == "true"; 
-        return;
-    case type::numeric: 
-        try
-        {
-            d_->numeric_value = std::stod(value);
-        }
-        catch(std::invalid_argument)
-        {
-            throw data_type_exception();
-        }
-        return;
-        */
-    case type::string: 
-        d_->string_value = value; 
-        return;
-    default: throw data_type_exception();
-    }
-}
-
-void cell::set_explicit_value(int value, type data_type)
-{
-    d_->type_ = data_type;
-
-    switch(data_type)
-    {
-        case type::numeric: d_->numeric_value = value; return;
-        //case type::string: d_->string_value = std::to_string(value); return;
-        default: throw data_type_exception();
-    }
-}
-
-void cell::set_explicit_value(double value, type data_type)
-{
-    d_->type_ = data_type;
-
-    switch(data_type)
-    {
-        case type::numeric: d_->numeric_value = value; return;
-        //case type::string: d_->string_value = std::to_string(value); return;
-        default: throw data_type_exception();
-    }
+    return cell_reference::column_string_from_index(d_->column_ + 1);
 }
 
 void cell::set_merged(bool merged)
@@ -289,7 +289,7 @@ bool cell::is_date() const
 
 cell_reference cell::get_reference() const
 {
-    return {d_->column, d_->row};
+    return {d_->column_, d_->row_};
 }
 
 bool cell::operator==(std::nullptr_t) const
@@ -297,68 +297,6 @@ bool cell::operator==(std::nullptr_t) const
     return d_ == nullptr;
 }
 
-bool cell::operator==(bool value) const
-{
-    return d_->type_ == type::boolean && (d_->numeric_value != 0) == value;
-}
-
-bool cell::operator==(int comparand) const
-{
-    return d_->type_ == type::numeric && d_->numeric_value == comparand;
-}
-
-bool cell::operator==(double comparand) const
-{
-    return d_->type_ == type::numeric && d_->numeric_value == comparand;
-}
-
-bool cell::operator==(const std::string &comparand) const
-{
-    if(d_->type_ == type::string)
-    {
-        return d_->string_value == comparand;
-    }
-
-    return false;
-}
-
-bool cell::operator==(const char *comparand) const
-{
-    return *this == std::string(comparand);
-}
-
-bool cell::operator==(const time &comparand) const
-{
-    if(d_->type_ != type::numeric)
-    {
-        return false;
-    }
-    
-    return time::from_number(d_->numeric_value) == comparand;
-}
-
-bool cell::operator==(const date &comparand) const
-{
-    if(d_->type_ != type::numeric)
-    {
-        return false;
-    }
-    
-    auto base_year = worksheet(d_->parent_).get_parent().get_properties().excel_base_date;
-    return date::from_number((int)d_->numeric_value, base_year) == comparand;
-}
-
-bool cell::operator==(const datetime &comparand) const
-{
-    if(d_->type_ != type::numeric)
-    {
-        return false;
-    }
-    
-    auto base_year = worksheet(d_->parent_).get_parent().get_properties().excel_base_date;
-    return datetime::from_number(d_->numeric_value, base_year) == comparand;
-}
-
 bool cell::operator==(const cell &comparand) const
 {
     if(comparand == nullptr)
@@ -366,67 +304,7 @@ bool cell::operator==(const cell &comparand) const
         return d_ == nullptr;
     }
 
-    if(comparand.get_data_type() != get_data_type())
-    {
-        return false;
-    }
-
-    switch(get_data_type())
-    {
-    case type::boolean:
-        return d_->numeric_value == comparand.d_->numeric_value;
-    case type::error:
-        return d_->string_value == comparand.d_->string_value;
-    case type::string:
-        return d_->string_value == comparand.d_->string_value;
-    case type::null:
-        return true;
-    case type::numeric:
-        if(is_date() && comparand.is_date())
-        {
-            auto base_year = worksheet(d_->parent_).get_parent().get_properties().excel_base_date;
-            auto other_base_year = worksheet(comparand.d_->parent_).get_parent().get_properties().excel_base_date;
-            return date::from_number((int)d_->numeric_value, base_year) == date::from_number((int)comparand.d_->numeric_value, other_base_year);
-        }
-        return d_->numeric_value == comparand.d_->numeric_value;
-    }
-
-    return false;
-}
-
-bool operator==(bool comparand, const xlnt::cell &cell)
-{
-    return cell == comparand;
-}
-    
-bool operator==(int comparand, const xlnt::cell &cell)
-{
-    return cell == comparand;
-}
-
-bool operator==(const char *comparand, const xlnt::cell &cell)
-{
-    return cell == comparand;
-}
-
-bool operator==(const std::string &comparand, const xlnt::cell &cell)
-{
-    return cell == comparand;
-}
-
-bool operator==(const time &comparand, const xlnt::cell &cell)
-{
-    return cell == comparand;
-}
-
-bool operator==(const date &comparand, const xlnt::cell &cell)
-{
-    return cell == comparand;
-}
-
-bool operator==(const datetime &comparand, const xlnt::cell &cell)
-{
-    return cell == comparand;
+    return d_->value_ == comparand.d_->value_;
 }
 
 style &cell::get_style()
@@ -447,158 +325,17 @@ const style &cell::get_style() const
     return *d_->style_;
 }
 
-xlnt::cell::type cell::get_data_type() const
-{
-    return (type)d_->type_;
-}
-
 cell &cell::operator=(const cell &rhs)
 {
     d_ = rhs.d_;
     return *this;
 }
 
-cell &cell::operator=(int value)
-{
-    d_->is_date_ = false;
-    d_->type_ = type::numeric;
-    d_->numeric_value = value;
-    return *this;
-}
-
-cell &cell::operator=(double value)
-{
-    d_->is_date_ = false;
-    d_->type_ = type::numeric;
-    d_->numeric_value = value;
-    return *this;
-}
-
-cell &cell::operator=(long int value)
-{
-    d_->is_date_ = false;
-    d_->type_ = type::numeric;
-    d_->numeric_value = value;
-    return *this;
-}
-
-cell &cell::operator=(long long value)
-{
-    d_->is_date_ = false;
-    d_->type_ = type::numeric;
-    d_->numeric_value = (long double)value;
-    return *this;
-}
-
-cell &cell::operator=(long double value)
-{
-    d_->is_date_ = false;
-    d_->type_ = type::numeric;
-    d_->numeric_value = value;
-    return *this;
-}
-
-cell &cell::operator=(bool value)
-{
-    d_->is_date_ = false;
-    d_->type_ = type::boolean;
-    d_->numeric_value = value ? 1 : 0;
-    return *this;
-}
-
 bool operator<(cell left, cell right)
 {
     return left.get_reference() < right.get_reference();
 }
 
-cell &cell::operator=(const std::string &value)
-{
-    if(!get_parent().get_parent().get_guess_types())
-    {
-        d_->is_date_ = false;
-        d_->type_ = type::string;
-        d_->string_value = value;
-    }
-    else
-    {
-        d_->is_date_ = false;
-        d_->type_ = data_type_for_value(value);
-
-        switch(d_->type_)
-        {
-        case type::numeric:
-            if(value.find(':') != std::string::npos)
-            {
-                d_->is_date_ = true;
-                d_->numeric_value = time(value).to_number();
-            }
-            else if(value.back() == '%')
-            {
-                d_->numeric_value = std::stod(value.substr(0, value.length() - 1)) / 100;
-                get_style().get_number_format().set_format_code(xlnt::number_format::format::percentage);
-            }
-            else
-            {
-                d_->numeric_value = std::stod(value);
-            }
-            break;
-        case type::boolean:
-            d_->numeric_value = value == "TRUE" || value == "true";
-            break;
-        case type::error:
-            d_->string_value = value;
-            break;
-        case type::string:
-            d_->string_value = value;
-            break;
-        case type::null:
-            break;
-        default: throw data_type_exception();
-        }
-    }
-    
-    return *this;
-}
-
-cell &cell::operator=(const char *value)
-{
-    return *this = std::string(value);
-}
-
-cell &cell::operator=(const time &value)
-{
-    d_->type_ = type::numeric;
-    d_->numeric_value = value.to_number();
-    d_->is_date_ = true;
-    return *this;
-}
-
-cell &cell::operator=(const date &value)
-{
-    d_->type_ = type::numeric;
-    auto base_year = worksheet(d_->parent_).get_parent().get_properties().excel_base_date;
-    d_->numeric_value = value.to_number(base_year);
-    d_->is_date_ = true;
-    return *this;
-}
-
-cell &cell::operator=(const datetime &value)
-{
-    d_->type_ = type::numeric;
-    auto base_year = worksheet(d_->parent_).get_parent().get_properties().excel_base_date;
-    d_->numeric_value = value.to_number(base_year);
-    d_->is_date_ = true;
-    return *this;
-}
-
-cell &cell::operator=(const timedelta &value)
-{
-    d_->type_ = type::numeric;
-    d_->numeric_value = value.to_number();
-    d_->is_date_ = true;
-    return *this;
-}
-
 std::string cell::to_string() const
 {
     return "<Cell " + worksheet(d_->parent_).get_title() + "." + get_reference().to_string() + ">";
@@ -629,17 +366,12 @@ void cell::set_hyperlink(const std::string &hyperlink)
     d_->has_hyperlink_ = true;
     d_->hyperlink_ = worksheet(d_->parent_).create_relationship(relationship::type::hyperlink, hyperlink);
 
-    if(d_->type_ == type::null)
+    if(get_value().is(value::type::null))
     {
-        *this = hyperlink;
+        set_value(hyperlink);
     }
 }
 
-void cell::set_null()
-{
-    d_->type_ = type::null;
-}
-
 void cell::set_formula(const std::string &formula)
 {
     if(formula.length() == 0)
@@ -647,27 +379,27 @@ void cell::set_formula(const std::string &formula)
         throw data_type_exception();
     }
 
-    d_->formula_value = formula;
+    d_->formula_ = formula;
 }
 
 bool cell::has_formula() const
 {
-    return !d_->formula_value.empty();
+    return !d_->formula_.empty();
 }
 
 std::string cell::get_formula() const
 {
-    if(d_->formula_value.empty())
+    if(d_->formula_.empty())
     {
         throw data_type_exception();
     }
 
-    return d_->formula_value;
+    return d_->formula_;
 }
 
 void cell::clear_formula()
 {
-    d_->formula_value.clear();
+    d_->formula_.clear();
 }
 
 void cell::set_comment(xlnt::comment &c)
@@ -737,13 +469,12 @@ void cell::set_error(const std::string &error)
         throw data_type_exception();
     }
 
-    d_->type_ = type::error;
-    d_->string_value = error;
+    set_value(value::error(error));
 }
 
 cell cell::offset(column_t column, row_t row)
 {
-    return get_parent().get_cell(cell_reference(d_->column + column, d_->row + row));
+    return get_parent().get_cell(cell_reference(d_->column_ + column, d_->row_ + row));
 }
     
 worksheet cell::get_parent()
@@ -751,9 +482,66 @@ worksheet cell::get_parent()
     return worksheet(d_->parent_);
 }
 
+const worksheet cell::get_parent() const
+{
+    return worksheet(d_->parent_);
+}
+
 comment cell::get_comment() const
 {
     return comment(&d_->comment_);
 }
 
+std::pair<int, int> cell::get_anchor() const
+{
+    static const double DefaultColumnWidth = 51.85;
+    static const double DefaultRowHeight = 15.0;
+
+    auto points_to_pixels = [](double value, double dpi) { return (int)std::ceil(value * dpi / 72); };
+
+    auto left_columns = d_->column_;
+    auto &column_dimensions = get_parent().get_column_dimensions();
+    int left_anchor = 0;
+    auto default_width = points_to_pixels(DefaultColumnWidth, 96.0);
+
+    for(int column_index = 1; column_index <= (int)left_columns; column_index++)
+    {
+        if(column_dimensions.find(column_index) != column_dimensions.end())
+        {
+            auto cdw = column_dimensions.at(column_index);
+
+            if(cdw > 0)
+            {
+                left_anchor += points_to_pixels(cdw, 96.0);
+                continue;
+            }
+        }
+
+        left_anchor += default_width;
+    }
+
+    auto top_rows = d_->row_;
+    auto &row_dimensions = get_parent().get_row_dimensions();
+    int top_anchor = 0;
+    auto default_height = points_to_pixels(DefaultRowHeight, 96.0);
+
+    for(int row_index = 1; row_index <= (int)top_rows; row_index++)
+    {
+        if(row_dimensions.find(row_index) != row_dimensions.end())
+        {
+            auto rdh = row_dimensions.at(row_index);
+
+            if(rdh > 0)
+            {
+                top_anchor += points_to_pixels(rdh, 96.0);
+                continue;
+            }
+        }
+
+        top_anchor += default_height;
+    }
+
+    return {left_anchor, top_anchor};
+}
+
 } // namespace xlnt
diff --git a/source/comment.cpp b/source/comment.cpp
new file mode 100644
index 00000000..0947f556
--- /dev/null
+++ b/source/comment.cpp
@@ -0,0 +1,47 @@
+#include "cell/comment.hpp"
+#include "detail/comment_impl.hpp"
+
+namespace xlnt {
+namespace detail {
+
+detail::comment_impl::comment_impl() : parent_worksheet_(nullptr)
+{
+}
+
+comment_impl::comment_impl(worksheet_impl *ws, const cell_reference &ref, const std::string &text, const std::string &author) : parent_worksheet_(ws), parent_cell_(ref), text_(text), author_(author)
+{
+
+}
+
+} // namespace detail
+
+comment::comment(const std::string &text, const std::string &author) : d_(new detail::comment_impl())
+{
+    d_->text_ = text;
+    d_->author_ = author;
+}
+
+comment::comment(detail::comment_impl *d) : d_(d)
+{
+}
+
+comment::~comment()
+{
+    if(d_->parent_worksheet_ == nullptr)
+    {
+        delete d_;
+        d_ = nullptr;
+    }
+}
+
+std::string comment::get_author() const
+{
+    return d_->author_;
+}
+
+std::string comment::get_text() const
+{
+    return d_->text_;
+}
+
+} // namespace xlnt
diff --git a/source/detail/cell_impl.cpp b/source/detail/cell_impl.cpp
index f572445a..d5992e69 100644
--- a/source/detail/cell_impl.cpp
+++ b/source/detail/cell_impl.cpp
@@ -4,15 +4,15 @@
 namespace xlnt {
 namespace detail {
 
-cell_impl::cell_impl() : parent_(nullptr), type_(cell::type::null), column(0), row(0), style_(nullptr), merged(false), has_hyperlink_(false), comment_(nullptr, "A1", "", "")
+cell_impl::cell_impl() : parent_(nullptr), column_(0), row_(0), style_(nullptr), merged(false), has_hyperlink_(false), comment_(nullptr, "A1", "", ""), is_date_(false)
 {
 }
     
-cell_impl::cell_impl(worksheet_impl *parent, int column_index, int row_index) : parent_(parent), type_(cell::type::null), column(column_index), row(row_index), style_(nullptr), merged(false), has_hyperlink_(false), comment_(nullptr, "A1", "", "")
+cell_impl::cell_impl(worksheet_impl *parent, int column_index, int row_index) : parent_(parent), column_(column_index), row_(row_index), style_(nullptr), merged(false), has_hyperlink_(false), comment_(nullptr, "A1", "", ""), is_date_(false)
 {
 }
     
-cell_impl::cell_impl(const cell_impl &rhs) : comment_(nullptr, "A1", "", "")
+cell_impl::cell_impl(const cell_impl &rhs) : comment_(nullptr, "A1", "", ""), is_date_(false)
 {
     *this = rhs;
 }
@@ -20,12 +20,11 @@ cell_impl::cell_impl(const cell_impl &rhs) : comment_(nullptr, "A1", "", "")
 cell_impl &cell_impl::operator=(const cell_impl &rhs)
 {
     parent_ = rhs.parent_;
-    type_ = rhs.type_;
-    numeric_value = rhs.numeric_value;
-    string_value = rhs.string_value;
+    value_ = rhs.value_;
     hyperlink_ = rhs.hyperlink_;
-    column = rhs.column;
-    row = rhs.row;
+    formula_ = rhs.formula_;
+    column_ = rhs.column_;
+    row_ = rhs.row_;
     style_ = rhs.style_;
     merged = rhs.merged;
     is_date_ = rhs.is_date_;
diff --git a/source/detail/cell_impl.hpp b/source/detail/cell_impl.hpp
index d1f3a2be..1073e9c9 100644
--- a/source/detail/cell_impl.hpp
+++ b/source/detail/cell_impl.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include "cell/cell.hpp"
+#include "cell/value.hpp"
 #include "common/types.hpp"
 #include "common/relationship.hpp"
 #include "comment_impl.hpp"
@@ -21,13 +22,11 @@ struct cell_impl
     cell_impl &operator=(const cell_impl &rhs);
 
     worksheet_impl *parent_;
-    cell::type type_;
-    long double numeric_value;
-    std::string string_value;
-    std::string formula_value;
+    value value_;
+    std::string formula_;
     relationship hyperlink_;
-    column_t column;
-    row_t row;
+    column_t column_;
+    row_t row_;
     style *style_;
     bool merged;
     bool is_date_;
diff --git a/source/detail/worksheet_impl.hpp b/source/detail/worksheet_impl.hpp
index 5faec50d..297fde33 100644
--- a/source/detail/worksheet_impl.hpp
+++ b/source/detail/worksheet_impl.hpp
@@ -65,6 +65,8 @@ struct worksheet_impl
     std::unordered_map<std::string, range_reference> named_ranges_;
     std::size_t comment_count_;
     header_footer header_footer_;
+    std::unordered_map<column_t, double> column_dimensions_;
+    std::unordered_map<row_t, double> row_dimensions_;
 };
 
 } // namespace detail
diff --git a/source/document_properties.cpp b/source/document_properties.cpp
index b47d378d..05fdec16 100644
--- a/source/document_properties.cpp
+++ b/source/document_properties.cpp
@@ -2,7 +2,10 @@
 
 namespace xlnt {
 
-document_properties::document_properties() : created(1900, 1, 1), modified(1900, 1, 1)
+document_properties::document_properties() 
+    : created(1900, 1, 1), 
+    modified(1900, 1, 1),
+    excel_base_date(calendar::windows_1900)
 {
 
 }
diff --git a/source/reader.cpp b/source/reader.cpp
index 8f37db50..768f9aec 100644
--- a/source/reader.cpp
+++ b/source/reader.cpp
@@ -3,6 +3,7 @@
 
 #include "reader/reader.hpp"
 #include "cell/cell.hpp"
+#include "cell/value.hpp"
 #include "common/datetime.hpp"
 #include "worksheet/range_reference.hpp"
 #include "workbook/workbook.hpp"
@@ -279,7 +280,7 @@ void read_worksheet_common(worksheet ws, const pugi::xml_node &root_node, const
             if(cell_node != nullptr)
             {
                 bool has_value = cell_node.child("v") != nullptr;
-                std::string value = cell_node.child("v").text().as_string();
+                std::string value_string = cell_node.child("v").text().as_string();
 
                 bool has_type = cell_node.attribute("t") != nullptr;
                 std::string type = cell_node.attribute("t").as_string();
@@ -299,36 +300,47 @@ void read_worksheet_common(worksheet ws, const pugi::xml_node &root_node, const
                 if(has_type && type == "inlineStr") // inline string
                 {
                     std::string inline_string = cell_node.child("is").child("t").text().as_string();
-                    ws.get_cell(address) = inline_string;
+                    ws.get_cell(address).set_value(inline_string);
                 }
                 else if(has_type && type == "s") // shared string
                 {
-                    ws.get_cell(address) = string_table.at(cell_node.child("v").text().as_int());
+                    auto shared_string_index = std::stoi(value_string);
+                    auto shared_string = string_table.at(shared_string_index);
+                    ws.get_cell(address).set_value(shared_string);
                 }
                 else if(has_type && type == "b") // boolean
                 {
-                    ws.get_cell(address) = value != "0";
+                    ws.get_cell(address).set_value(value(value_string != "0"));
                 }
                 else if(has_type && type == "str")
                 {
-                    ws.get_cell(address) = value;
+                    ws.get_cell(address).set_value(value_string);
                 }
                 else if(has_style)
                 {
                     auto number_format_id = number_format_ids.at(std::stoi(style));
                     auto format = number_format::lookup_format(number_format_id);
                     ws.get_cell(address).get_style().get_number_format().set_format_code(format);
-                    ws.get_cell(address) = std::stod(value);
+                    if(format == number_format::format::date_xlsx14)
+                    {
+                        auto base_date = ws.get_parent().get_properties().excel_base_date;
+                        auto converted = date::from_number(std::stoi(value_string), base_date);
+                        ws.get_cell(address).set_value(converted.to_number(calendar::windows_1900));
+                    }
+                    else
+                    {
+                        ws.get_cell(address).set_value(value(std::stod(value_string)));
+                    }
                 }
                 else if(has_value)
                 {
                     try
                     {
-                        ws.get_cell(address) = std::stod(value);
+                        ws.get_cell(address).set_value(value(std::stod(value_string)));
                     }
                     catch(std::invalid_argument)
                     {
-                        ws.get_cell(address) = value;
+                        ws.get_cell(address).set_value(value_string);
                     }
                 }
             }
diff --git a/source/value.cpp b/source/value.cpp
new file mode 100644
index 00000000..5bd16f78
--- /dev/null
+++ b/source/value.cpp
@@ -0,0 +1,314 @@
+#include "cell/value.hpp"
+#include "common/datetime.hpp"
+
+namespace xlnt {
+
+value value::error(const std::string &error_string)
+{
+    value v(error_string);
+    v.type_ = type::error;
+    return v;
+}
+
+value::value() : type_(type::null), numeric_value_(0)
+{
+}
+
+value::value(value &&v)
+{
+    swap(*this, v);
+}
+
+value::value(bool b) : type_(type::boolean), numeric_value_(b ? 1 : 0)
+{
+}
+
+value::value(int i) : type_(type::numeric), numeric_value_(i)
+{
+}
+
+value::value(double d) : type_(type::numeric), numeric_value_(d)
+{
+}
+
+value::value(int64_t i) : type_(type::numeric), numeric_value_((long double)i)
+{
+}
+
+value::value(const char *s) : value(std::string(s))
+{
+}
+
+value::value(const std::string &s) : type_(type::string), string_value_(s)
+{
+}
+
+value &value::operator=(value other)
+{
+    swap(*this, other);
+    return *this;
+}
+
+bool value::is(type t) const
+{
+    return type_ == t;
+}
+
+template<>
+double value::as() const
+{
+    switch(type_)
+    {
+    case type::boolean:
+    case type::numeric:
+        return (double)numeric_value_;
+    case type::string:
+        return std::stod(string_value_);
+    case type::error:
+        throw std::runtime_error("invalid");
+    case type::null:
+        return 0;
+    }
+
+    return 0;
+}
+
+template<>
+int value::as() const
+{
+    switch(type_)
+    {
+    case type::boolean:
+    case type::numeric:
+        return (int)numeric_value_;
+    case type::string:
+        return std::stoi(string_value_);
+    case type::error:
+        throw std::runtime_error("invalid");
+    case type::null:
+        return 0;
+    }
+
+    return 0;
+}
+
+template<>
+int64_t value::as() const
+{
+    switch(type_)
+    {
+    case type::boolean:
+    case type::numeric:
+        return (int64_t)numeric_value_;
+    case type::string:
+        return std::stoi(string_value_);
+    case type::error:
+        throw std::runtime_error("invalid");
+    case type::null:
+        return 0;
+    }
+
+    return 0;
+}
+
+template<>
+bool value::as() const
+{
+    switch(type_)
+    {
+    case type::boolean:
+    case type::numeric:
+        return numeric_value_ != 0;
+    case type::string:
+        return !string_value_.empty();
+    case type::error:
+        throw std::runtime_error("invalid");
+    case type::null:
+        return false;
+    }
+
+    return false;
+}
+
+bool value::is_integral() const
+{
+    return type_ == type::numeric && (int64_t)numeric_value_ == numeric_value_;
+}
+
+template<>
+std::string value::as() const
+{
+    return to_string();
+}
+
+value value::null()
+{
+    return value();
+}
+
+value::type value::get_type() const
+{
+    return type_;
+}
+
+std::string value::to_string() const
+{
+    switch(type_)
+    {
+    case type::boolean:
+        return numeric_value_ != 0 ? "1" : "0";
+    case type::numeric:
+        return std::to_string(numeric_value_);
+    case type::string:
+    case type::error:
+        return string_value_;
+    case type::null:
+        return "";
+    }
+
+    return "";
+}
+
+bool value::operator==(bool value) const
+{
+    return type_ == type::boolean && (numeric_value_ != 0) == value;
+}
+
+bool value::operator==(int comparand) const
+{
+    return type_ == type::numeric && numeric_value_ == comparand;
+}
+
+bool value::operator==(double comparand) const
+{
+    return type_ == type::numeric && numeric_value_ == comparand;
+}
+
+bool value::operator==(const std::string &comparand) const
+{
+    if(type_ == type::string)
+    {
+        return string_value_ == comparand;
+    }
+
+    return false;
+}
+
+bool value::operator==(const char *comparand) const
+{
+    return *this == std::string(comparand);
+}
+
+bool value::operator==(const time &comparand) const
+{
+    if(type_ != type::numeric)
+    {
+        return false;
+    }
+
+    return time::from_number(numeric_value_) == comparand;
+}
+
+bool value::operator==(const date &comparand) const
+{
+    return type_ == type::numeric && comparand.to_number(calendar::windows_1900) == numeric_value_;
+}
+
+bool value::operator==(const datetime &comparand) const
+{
+    return type_ == type::numeric && comparand.to_number(calendar::windows_1900) == numeric_value_;
+}
+
+bool value::operator==(const timedelta &comparand) const
+{
+    return type_ == type::numeric && comparand.to_number() == numeric_value_;
+}
+
+bool value::operator==(const value &v) const
+{
+    if(type_ != v.type_) return false;
+    if(type_ == type::string || type_ == type::error) return string_value_ == v.string_value_;
+    if(type_ == type::numeric || type_ == type::boolean) return numeric_value_ == v.numeric_value_;
+    return true;
+}
+
+/*
+value &value::operator=(const time &value)
+{
+    d_->type_ = type::numeric;
+    d_->numeric_value = value.to_number();
+    d_->is_date_ = true;
+    return *this;
+}
+
+value &value::operator=(const date &value)
+{
+    d_->type_ = type::numeric;
+    auto base_year = worksheet(d_->parent_).get_parent().get_properties().excel_base_date;
+    d_->numeric_value = value.to_number(base_year);
+    d_->is_date_ = true;
+    return *this;
+}
+
+value &value::operator=(const datetime &value)
+{
+    d_->type_ = type::numeric;
+    auto base_year = worksheet(d_->parent_).get_parent().get_properties().excel_base_date;
+    d_->numeric_value = value.to_number(base_year);
+    d_->is_date_ = true;
+    return *this;
+}
+
+value &value::operator=(const timedelta &value)
+{
+    d_->type_ = type::numeric;
+    d_->numeric_value = value.to_number();
+    d_->is_date_ = true;
+    return *this;
+}
+*/
+
+bool operator==(bool comparand, const xlnt::value &value)
+{
+    return value == comparand;
+}
+
+bool operator==(int comparand, const xlnt::value &value)
+{
+    return value == comparand;
+}
+
+bool operator==(const char *comparand, const xlnt::value &value)
+{
+    return value == comparand;
+}
+
+bool operator==(const std::string &comparand, const xlnt::value &value)
+{
+    return value == comparand;
+}
+
+bool operator==(const time &comparand, const xlnt::value &value)
+{
+    return value == comparand;
+}
+
+bool operator==(const date &comparand, const xlnt::value &value)
+{
+    return value == comparand;
+}
+
+bool operator==(const datetime &comparand, const xlnt::value &value)
+{
+    return value == comparand;
+}
+
+void swap(value &left, value &right)
+{
+    using std::swap;
+    swap(left.type_, right.type_);
+    swap(left.string_value_, right.string_value_);
+    swap(left.numeric_value_, right.numeric_value_);
+}
+
+} // namespace xlnt
diff --git a/source/worksheet.cpp b/source/worksheet.cpp
index aa573839..65f34994 100644
--- a/source/worksheet.cpp
+++ b/source/worksheet.cpp
@@ -2,6 +2,7 @@
 
 #include "worksheet/worksheet.hpp"
 #include "cell/cell.hpp"
+#include "cell/value.hpp"
 #include "common/datetime.hpp"
 #include "worksheet/range.hpp"
 #include "worksheet/range_reference.hpp"
@@ -108,7 +109,7 @@ void worksheet::garbage_collect()
         {
             cell current_cell(&cell_iter->second);
 
-            if(current_cell.get_data_type() == cell::type::null && !current_cell.has_comment())
+            if(current_cell.garbage_collectible())
             {
                 cell_iter = cell_map_iter->second.erase(cell_iter);
                 continue;
@@ -174,6 +175,16 @@ void worksheet::unfreeze_panes()
     d_->freeze_panes_ = cell_reference("A1");
 }
 
+const std::unordered_map<column_t, double> &worksheet::get_column_dimensions() const
+{
+    return d_->column_dimensions_;
+}
+
+const std::unordered_map<row_t, double> &worksheet::get_row_dimensions() const
+{
+    return d_->row_dimensions_;
+}
+
 cell worksheet::get_cell(const cell_reference &reference)
 {
     if(d_->cell_map_.find(reference.get_row_index()) == d_->cell_map_.end())
@@ -323,10 +334,19 @@ void worksheet::merge_cells(const range_reference &reference)
         for(auto cell : row)
         {
             cell.set_merged(true);
+
             if(!first)
             {
-	        cell.set_null();
+                if(cell.get_value().is(value::type::string))
+                {
+                    cell.set_value(value(""));
+                }
+                else
+                {
+                    cell.set_value(value::null());
+                }
             }
+
             first = false;
         }
     }
@@ -365,7 +385,7 @@ void worksheet::append(const std::vector<std::string> &cells)
     
     for(auto cell : cells)
     {
-        this->get_cell(cell_reference(column++, row)) = cell;
+        get_cell(cell_reference(column++, row)).set_value(cell);
     }
 }
 
@@ -382,7 +402,7 @@ void worksheet::append(const std::vector<int> &cells)
     
     for(auto cell : cells)
     {
-        this->get_cell(cell_reference(column++, row)) = cell;
+        get_cell(cell_reference(column++, row)).set_value(value(cell));
     }
 }
 
@@ -399,7 +419,7 @@ void worksheet::append(const std::vector<date> &cells)
     
     for(auto cell : cells)
     {
-        this->get_cell(cell_reference(column++, row)) = cell;
+        get_cell(cell_reference(column++, row)).set_value(cell);
     }
 }
 
@@ -414,7 +434,7 @@ void worksheet::append(const std::unordered_map<std::string, std::string> &cells
 
     for(auto cell : cells)
     {
-        this->get_cell(cell_reference(cell.first, row + 1)) = cell.second;
+        get_cell(cell_reference(cell.first, row + 1)).set_value(cell.second);
     }
 }
 
@@ -429,7 +449,7 @@ void worksheet::append(const std::unordered_map<int, std::string> &cells)
 
     for(auto cell : cells)
     {
-        this->get_cell(cell_reference(cell.first, row)) = cell.second;
+        get_cell(cell_reference(cell.first, row)).set_value(cell.second);
     }
 }
 
@@ -558,4 +578,64 @@ std::vector<std::string> worksheet::get_formula_attributes() const
     return {};
 }
 
+cell_reference worksheet::get_point_pos(int left, int top) const
+{
+    static const double DefaultColumnWidth = 51.85;
+    static const double DefaultRowHeight = 15.0;
+
+    auto points_to_pixels = [](double value, double dpi) { return (int)std::ceil(value * dpi / 72); };
+    
+    auto default_height = points_to_pixels(DefaultRowHeight, 96.0);
+    auto default_width = points_to_pixels(DefaultColumnWidth, 96.0);
+
+    column_t current_column = 0;
+    row_t current_row = 0;
+
+    int left_pos = 0;
+    int top_pos = 0;
+
+    while(left_pos <= left)
+    {
+        current_column++;
+
+        if(d_->column_dimensions_.find(current_column) != d_->column_dimensions_.end())
+        {
+            auto cdw = d_->column_dimensions_.at(current_column);
+
+            if(cdw >= 0)
+            {
+                left_pos += points_to_pixels(cdw, 96.0);
+                continue;
+            }
+        }
+
+        left_pos += default_width;
+    }
+
+    while(top_pos <= top)
+    {
+        current_row++;
+
+        if(d_->row_dimensions_.find(current_row) != d_->row_dimensions_.end())
+        {
+            auto cdh = d_->column_dimensions_.at(current_row);
+
+            if(cdh >= 0)
+            {
+                top_pos += points_to_pixels(cdh, 96.0);
+                continue;
+            }
+        }
+
+        top_pos += default_height;
+    }
+
+    return {current_column - 1, current_row - 1};
+}
+
+cell_reference worksheet::get_point_pos(const std::pair<int, int> &point) const
+{
+    return get_point_pos(point.first, point.second);
+}
+
 } // namespace xlnt
diff --git a/source/writer.cpp b/source/writer.cpp
index 4d362673..95b0f41d 100644
--- a/source/writer.cpp
+++ b/source/writer.cpp
@@ -9,6 +9,7 @@
 
 #include "writer/writer.hpp"
 #include "cell/cell.hpp"
+#include "cell/value.hpp"
 #include "constants.hpp"
 #include "worksheet/range.hpp"
 #include "worksheet/range_reference.hpp"
@@ -313,7 +314,7 @@ std::string writer::write_worksheet(worksheet ws, const std::vector<std::string>
             min = std::min(min, cell_reference::column_index_from_string(cell.get_column()));
             max = std::max(max, cell_reference::column_index_from_string(cell.get_column()));
             
-            if(cell.get_data_type() != cell::type::null || cell.is_merged() || cell.has_comment() || cell.has_formula())
+            if(!cell.garbage_collectible())
             {
                 any_non_null = true;
             }
@@ -345,7 +346,7 @@ std::string writer::write_worksheet(worksheet ws, const std::vector<std::string>
         
         for(auto cell : row)
         {
-            if(cell.get_data_type() != cell::type::null || cell.is_merged() || cell.has_comment() || cell.has_formula())
+            if(!cell.garbage_collectible())
             {
                 if(cell.has_hyperlink())
                 {
@@ -355,20 +356,20 @@ std::string writer::write_worksheet(worksheet ws, const std::vector<std::string>
                 auto cell_node = row_node.append_child("c");
                 cell_node.append_attribute("r").set_value(cell.get_reference().to_string().c_str());
                 
-                if(cell.get_data_type() == cell::type::string)
+                if(cell.get_value().is(value::type::string))
                 {
                     if(cell.has_formula())
                     {
                         cell_node.append_attribute("t").set_value("str");
                         cell_node.append_child("f").text().set(cell.get_formula().c_str());
-                        cell_node.append_child("v").text().set(cell.get_internal_value_string().c_str());
+                        cell_node.append_child("v").text().set(cell.get_value().to_string().c_str());
                         continue;
                     }
 
                     int match_index = -1;
                     for(int i = 0; i < (int)string_table.size(); i++)
                     {
-                        if(string_table[i] == cell.get_internal_value_string())
+                        if(string_table[i] == cell.get_value().as<std::string>())
                         {
                             match_index = i;
                             break;
@@ -377,9 +378,16 @@ std::string writer::write_worksheet(worksheet ws, const std::vector<std::string>
                     
                     if(match_index == -1)
                     {
-                        cell_node.append_attribute("t").set_value("inlineStr");
-                        auto inline_string_node = cell_node.append_child("is");
-                        inline_string_node.append_child("t").text().set(cell.get_internal_value_string().c_str());
+                        if(cell.get_value().as<std::string>().empty())
+                        {
+                            cell_node.append_attribute("t").set_value("s");
+                        }
+                        else
+                        {
+                            cell_node.append_attribute("t").set_value("inlineStr");
+                            auto inline_string_node = cell_node.append_child("is");
+                            inline_string_node.append_child("t").text().set(cell.get_value().as<std::string>().c_str());
+                        }
                     }
                     else
                     {
@@ -390,32 +398,32 @@ std::string writer::write_worksheet(worksheet ws, const std::vector<std::string>
                 }
                 else
                 {
-                    if(cell.get_data_type() != cell::type::null)
+                    if(!cell.get_value().is(value::type::null))
                     {
-                        if(cell.get_data_type() == cell::type::boolean)
+                        if(cell.get_value().is(value::type::boolean))
                         {
                             cell_node.append_attribute("t").set_value("b");
                             auto value_node = cell_node.append_child("v");
-                            value_node.text().set(cell.get_internal_value_numeric() == 0 ? 0 : 1);
+                            value_node.text().set(cell.get_value().as<bool>() ? 1 : 0);
                         }
-                        else if(cell.get_data_type() == cell::type::numeric)
+                        else if(cell.get_value().is(value::type::numeric))
                         {
                             if(cell.has_formula())
                             {
                                 cell_node.append_child("f").text().set(cell.get_formula().c_str());
-                                cell_node.append_child("v").text().set(std::to_string(cell.get_internal_value_numeric()).c_str());
+                                cell_node.append_child("v").text().set(cell.get_value().to_string().c_str());
                                 continue;
                             }
 
                             cell_node.append_attribute("t").set_value("n");
                             auto value_node = cell_node.append_child("v");
-                            if(std::floor(cell.get_internal_value_numeric()) == cell.get_internal_value_numeric())
+                            if(cell.get_value().is_integral())
                             {
-                                value_node.text().set((long long)cell.get_internal_value_numeric());
+                                value_node.text().set(cell.get_value().as<long long>());
                             }
                             else
                             {
-                                value_node.text().set((double)cell.get_internal_value_numeric());
+                                value_node.text().set(cell.get_value().as<double>());
                             }
                         }
                     }
diff --git a/tests/runner-autogen.cpp b/tests/runner-autogen.cpp
index 3df74792..674d267a 100644
--- a/tests/runner-autogen.cpp
+++ b/tests/runner-autogen.cpp
@@ -204,61 +204,61 @@ public:
 
 static class TestDescription_suite_test_cell_test_time : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_cell_test_time() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 326, "test_time" ) {}
+ TestDescription_suite_test_cell_test_time() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 321, "test_time" ) {}
  void runTest() { suite_test_cell.test_time(); }
 } testDescription_suite_test_cell_test_time;
 
 static class TestDescription_suite_test_cell_test_timedelta : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_cell_test_timedelta() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 340, "test_timedelta" ) {}
+ TestDescription_suite_test_cell_test_timedelta() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 335, "test_timedelta" ) {}
  void runTest() { suite_test_cell.test_timedelta(); }
 } testDescription_suite_test_cell_test_timedelta;
 
 static class TestDescription_suite_test_cell_test_date_format_on_non_date : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_cell_test_date_format_on_non_date() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 350, "test_date_format_on_non_date" ) {}
+ TestDescription_suite_test_cell_test_date_format_on_non_date() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 345, "test_date_format_on_non_date" ) {}
  void runTest() { suite_test_cell.test_date_format_on_non_date(); }
 } testDescription_suite_test_cell_test_date_format_on_non_date;
 
 static class TestDescription_suite_test_cell_test_set_get_date : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_cell_test_set_get_date() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 360, "test_set_get_date" ) {}
+ TestDescription_suite_test_cell_test_set_get_date() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 355, "test_set_get_date" ) {}
  void runTest() { suite_test_cell.test_set_get_date(); }
 } testDescription_suite_test_cell_test_set_get_date;
 
 static class TestDescription_suite_test_cell_test_repr : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_cell_test_repr() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 371, "test_repr" ) {}
+ TestDescription_suite_test_cell_test_repr() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 366, "test_repr" ) {}
  void runTest() { suite_test_cell.test_repr(); }
 } testDescription_suite_test_cell_test_repr;
 
 static class TestDescription_suite_test_cell_test_is_date : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_cell_test_is_date() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 379, "test_is_date" ) {}
+ TestDescription_suite_test_cell_test_is_date() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 374, "test_is_date" ) {}
  void runTest() { suite_test_cell.test_is_date(); }
 } testDescription_suite_test_cell_test_is_date;
 
 static class TestDescription_suite_test_cell_test_is_not_date_color_format : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_cell_test_is_not_date_color_format() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 393, "test_is_not_date_color_format" ) {}
+ TestDescription_suite_test_cell_test_is_not_date_color_format() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 388, "test_is_not_date_color_format" ) {}
  void runTest() { suite_test_cell.test_is_not_date_color_format(); }
 } testDescription_suite_test_cell_test_is_not_date_color_format;
 
 static class TestDescription_suite_test_cell_test_comment_count : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_cell_test_comment_count() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 404, "test_comment_count" ) {}
+ TestDescription_suite_test_cell_test_comment_count() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 399, "test_comment_count" ) {}
  void runTest() { suite_test_cell.test_comment_count(); }
 } testDescription_suite_test_cell_test_comment_count;
 
 static class TestDescription_suite_test_cell_test_comment_assignment : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_cell_test_comment_assignment() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 420, "test_comment_assignment" ) {}
+ TestDescription_suite_test_cell_test_comment_assignment() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 415, "test_comment_assignment" ) {}
  void runTest() { suite_test_cell.test_comment_assignment(); }
 } testDescription_suite_test_cell_test_comment_assignment;
 
 static class TestDescription_suite_test_cell_test_cell_offset : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_cell_test_cell_offset() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 434, "test_cell_offset" ) {}
+ TestDescription_suite_test_cell_test_cell_offset() : CxxTest::RealTestDescription( Tests_test_cell, suiteDescription_test_cell, 429, "test_cell_offset" ) {}
  void runTest() { suite_test_cell.test_cell_offset(); }
 } testDescription_suite_test_cell_test_cell_offset;
 
@@ -723,69 +723,63 @@ public:
  void runTest() { suite_test_read.test_read_cell_formulae(); }
 } testDescription_suite_test_read_test_read_cell_formulae;
 
-static class TestDescription_suite_test_read_test_read_complex_formulae : public CxxTest::RealTestDescription {
-public:
- TestDescription_suite_test_read_test_read_complex_formulae() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 223, "test_read_complex_formulae" ) {}
- void runTest() { suite_test_read.test_read_complex_formulae(); }
-} testDescription_suite_test_read_test_read_complex_formulae;
-
 static class TestDescription_suite_test_read_test_data_only : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_read_test_data_only() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 282, "test_data_only" ) {}
+ TestDescription_suite_test_read_test_data_only() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 280, "test_data_only" ) {}
  void runTest() { suite_test_read.test_data_only(); }
 } testDescription_suite_test_read_test_data_only;
 
 static class TestDescription_suite_test_read_test_detect_worksheets : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_read_test_detect_worksheets() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 304, "test_detect_worksheets" ) {}
+ TestDescription_suite_test_read_test_detect_worksheets() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 302, "test_detect_worksheets" ) {}
  void runTest() { suite_test_read.test_detect_worksheets(); }
 } testDescription_suite_test_read_test_detect_worksheets;
 
 static class TestDescription_suite_test_read_test_read_rels : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_read_test_read_rels() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 344, "test_read_rels" ) {}
+ TestDescription_suite_test_read_test_read_rels() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 342, "test_read_rels" ) {}
  void runTest() { suite_test_read.test_read_rels(); }
 } testDescription_suite_test_read_test_read_rels;
 
 static class TestDescription_suite_test_read_test_read_content_types : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_read_test_read_content_types() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 382, "test_read_content_types" ) {}
+ TestDescription_suite_test_read_test_read_content_types() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 380, "test_read_content_types" ) {}
  void runTest() { suite_test_read.test_read_content_types(); }
 } testDescription_suite_test_read_test_read_content_types;
 
 static class TestDescription_suite_test_read_test_read_sheets : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_read_test_read_sheets() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 418, "test_read_sheets" ) {}
+ TestDescription_suite_test_read_test_read_sheets() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 416, "test_read_sheets" ) {}
  void runTest() { suite_test_read.test_read_sheets(); }
 } testDescription_suite_test_read_test_read_sheets;
 
 static class TestDescription_suite_test_read_test_guess_types : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_read_test_guess_types() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 439, "test_guess_types" ) {}
+ TestDescription_suite_test_read_test_guess_types() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 437, "test_guess_types" ) {}
  void runTest() { suite_test_read.test_guess_types(); }
 } testDescription_suite_test_read_test_guess_types;
 
 static class TestDescription_suite_test_read_test_read_autofilter : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_read_test_read_autofilter() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 455, "test_read_autofilter" ) {}
+ TestDescription_suite_test_read_test_read_autofilter() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 453, "test_read_autofilter" ) {}
  void runTest() { suite_test_read.test_read_autofilter(); }
 } testDescription_suite_test_read_test_read_autofilter;
 
 static class TestDescription_suite_test_read_test_bad_formats_xlsb : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_read_test_bad_formats_xlsb() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 463, "test_bad_formats_xlsb" ) {}
+ TestDescription_suite_test_read_test_bad_formats_xlsb() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 461, "test_bad_formats_xlsb" ) {}
  void runTest() { suite_test_read.test_bad_formats_xlsb(); }
 } testDescription_suite_test_read_test_bad_formats_xlsb;
 
 static class TestDescription_suite_test_read_test_bad_formats_xls : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_read_test_bad_formats_xls() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 469, "test_bad_formats_xls" ) {}
+ TestDescription_suite_test_read_test_bad_formats_xls() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 467, "test_bad_formats_xls" ) {}
  void runTest() { suite_test_read.test_bad_formats_xls(); }
 } testDescription_suite_test_read_test_bad_formats_xls;
 
 static class TestDescription_suite_test_read_test_bad_formats_no : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_read_test_bad_formats_no() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 475, "test_bad_formats_no" ) {}
+ TestDescription_suite_test_read_test_bad_formats_no() : CxxTest::RealTestDescription( Tests_test_read, suiteDescription_test_read, 473, "test_bad_formats_no" ) {}
  void runTest() { suite_test_read.test_bad_formats_no(); }
 } testDescription_suite_test_read_test_bad_formats_no;
 
@@ -1222,49 +1216,49 @@ public:
 
 static class TestDescription_suite_test_worksheet_test_page_margins : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_worksheet_test_page_margins() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 311, "test_page_margins" ) {}
+ TestDescription_suite_test_worksheet_test_page_margins() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 330, "test_page_margins" ) {}
  void runTest() { suite_test_worksheet.test_page_margins(); }
 } testDescription_suite_test_worksheet_test_page_margins;
 
 static class TestDescription_suite_test_worksheet_test_merge : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_worksheet_test_merge() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 323, "test_merge" ) {}
+ TestDescription_suite_test_worksheet_test_merge() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 368, "test_merge" ) {}
  void runTest() { suite_test_worksheet.test_merge(); }
 } testDescription_suite_test_worksheet_test_merge;
 
 static class TestDescription_suite_test_worksheet_test_printer_settings : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_worksheet_test_printer_settings() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 335, "test_printer_settings" ) {}
+ TestDescription_suite_test_worksheet_test_printer_settings() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 477, "test_printer_settings" ) {}
  void runTest() { suite_test_worksheet.test_printer_settings(); }
 } testDescription_suite_test_worksheet_test_printer_settings;
 
 static class TestDescription_suite_test_worksheet_test_header_footer : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_worksheet_test_header_footer() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 357, "test_header_footer" ) {}
+ TestDescription_suite_test_worksheet_test_header_footer() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 497, "test_header_footer" ) {}
  void runTest() { suite_test_worksheet.test_header_footer(); }
 } testDescription_suite_test_worksheet_test_header_footer;
 
 static class TestDescription_suite_test_worksheet_test_positioning_point : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_worksheet_test_positioning_point() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 434, "test_positioning_point" ) {}
+ TestDescription_suite_test_worksheet_test_positioning_point() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 574, "test_positioning_point" ) {}
  void runTest() { suite_test_worksheet.test_positioning_point(); }
 } testDescription_suite_test_worksheet_test_positioning_point;
 
 static class TestDescription_suite_test_worksheet_test_positioning_roundtrip : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_worksheet_test_positioning_roundtrip() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 442, "test_positioning_roundtrip" ) {}
+ TestDescription_suite_test_worksheet_test_positioning_roundtrip() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 580, "test_positioning_roundtrip" ) {}
  void runTest() { suite_test_worksheet.test_positioning_roundtrip(); }
 } testDescription_suite_test_worksheet_test_positioning_roundtrip;
 
 static class TestDescription_suite_test_worksheet_test_page_setup : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_worksheet_test_page_setup() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 453, "test_page_setup" ) {}
+ TestDescription_suite_test_worksheet_test_page_setup() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 588, "test_page_setup" ) {}
  void runTest() { suite_test_worksheet.test_page_setup(); }
 } testDescription_suite_test_worksheet_test_page_setup;
 
 static class TestDescription_suite_test_worksheet_test_page_options : public CxxTest::RealTestDescription {
 public:
- TestDescription_suite_test_worksheet_test_page_options() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 464, "test_page_options" ) {}
+ TestDescription_suite_test_worksheet_test_page_options() : CxxTest::RealTestDescription( Tests_test_worksheet, suiteDescription_test_worksheet, 596, "test_page_options" ) {}
  void runTest() { suite_test_worksheet.test_page_options(); }
 } testDescription_suite_test_worksheet_test_page_options;
 
diff --git a/tests/test_cell.hpp b/tests/test_cell.hpp
index 57e05ab0..9127791a 100644
--- a/tests/test_cell.hpp
+++ b/tests/test_cell.hpp
@@ -100,7 +100,7 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1", "17.5");
 
-        TS_ASSERT_EQUALS(xlnt::cell::type::string, cell.get_data_type());
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::string));
     }
 
     void test_1st()
@@ -108,16 +108,16 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
 
-        TS_ASSERT_EQUALS(xlnt::cell::type::null, cell.get_data_type());
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::null));
     }
 
     void test_null()
     {
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1", "17.5");
-        cell.set_null();
+        cell.set_value(xlnt::value::null());
 
-        TS_ASSERT_EQUALS(xlnt::cell::type::null, cell.get_data_type());
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::null));
     }
 
     void test_numeric()
@@ -127,41 +127,41 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
 
-        cell = 42;
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value(42);
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = "4.2";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value("4.2");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = "-42.000";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value("-42.000");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = "0";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value("0");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = 0;
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value(0);
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = 0.0001;
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value(0.0001);
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = "0.9999";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value("0.9999");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = "99E-02";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value("99E-02");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = 1e1;
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value(1e1);
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = "4";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value("4");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = "-1E3";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value("-1E3");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = 4;
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value(4);
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
     }
 
     void test_string()
@@ -169,16 +169,16 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
 
-        cell = "hello";
-        TS_ASSERT_EQUALS(xlnt::cell::type::string, cell.get_data_type());
+        cell.set_value("hello");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::string));
     }
 
     void test_single_dot()
     {
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
-        cell = ".";
-        TS_ASSERT_EQUALS(xlnt::cell::type::string, cell.get_data_type());
+        cell.set_value(".");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::string));
     }
 
     void test_formula()
@@ -197,18 +197,18 @@ public:
     {
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
-        cell = true;
-        TS_ASSERT_EQUALS(xlnt::cell::type::boolean, cell.get_data_type());
-        cell = false;
-        TS_ASSERT_EQUALS(xlnt::cell::type::boolean, cell.get_data_type());
+        cell.set_value(true);
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::boolean));
+        cell.set_value(false);
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::boolean));
     }
 
     void test_leading_zero()
     {
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
-        cell = "0800";
-        TS_ASSERT_EQUALS(xlnt::cell::type::string, cell.get_data_type());
+        cell.set_value("0800");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::string));
     }
 
     void test_error_codes()
@@ -218,8 +218,8 @@ public:
 
         for(auto error : xlnt::cell::ErrorCodes)
         {
-            cell = error.first;
-            TS_ASSERT_EQUALS(xlnt::cell::type::error, cell.get_data_type());
+            cell.set_error(error.first);
+            TS_ASSERT(cell.get_value().is(xlnt::value::type::error));
         }
     }
 
@@ -227,32 +227,32 @@ public:
     {
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
-        cell = 3.14;
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value(3.14);
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
     }
 
     void test_insert_percentage()
     {
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
-        cell = "3.14%";
-        TS_ASSERT_DELTA(0.0314, cell.get_internal_value_numeric(), 1e-7);
+        cell.set_value("3.14%");
+        TS_ASSERT_DELTA(0.0314, cell.get_value().as<double>(), 1e-7);
     }
 
     void test_insert_datetime()
     {
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
-        cell = xlnt::date::today();
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value(xlnt::date::today());
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
     }
 
     void test_insert_date()
     {
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
-        cell = xlnt::datetime::now();
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value(xlnt::datetime::now());
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
     }
 
     void test_internal_date()
@@ -260,8 +260,8 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
         xlnt::datetime dt(2010, 7, 13, 6, 37, 41);
-        cell = dt;
-        TS_ASSERT_EQUALS(40372.27616898148, cell.get_internal_value_numeric());
+        cell.set_value(dt);
+        TS_ASSERT_EQUALS(40372.27616898148, cell.get_value().as<double>());
     }
 
     void test_datetime_interpretation()
@@ -269,9 +269,9 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
         xlnt::datetime dt(2010, 7, 13, 6, 37, 41);
-        cell = dt;
-        TS_ASSERT_EQUALS(cell, dt);
-        TS_ASSERT_DELTA(cell.get_internal_value_numeric(), 40372.27616898148, 1e-7);
+        cell.set_value(dt);
+        TS_ASSERT_EQUALS(cell.get_value(), dt);
+        TS_ASSERT_DELTA(cell.get_value().as<double>(), 40372.27616898148, 1e-7);
     }
 
     void test_date_interpretation()
@@ -279,16 +279,16 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
         xlnt::date dt(2010, 7, 13);
-        cell = dt;
-        TS_ASSERT_EQUALS(cell, dt);
-        TS_ASSERT_EQUALS(cell.get_internal_value_numeric(), 40372);
+        cell.set_value(dt);
+        TS_ASSERT_EQUALS(cell.get_value(), dt);
+        TS_ASSERT_EQUALS(cell.get_value().as<int>(), 40372);
     }
 
     void test_number_format_style()
     {
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
-        cell = "12.6%";
+        cell.set_value("12.6%");
         TS_ASSERT_EQUALS(xlnt::number_format::format::percentage, cell.get_style().get_number_format().get_format_code());
     }
 
@@ -297,27 +297,22 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
 
-        TS_ASSERT_EQUALS(xlnt::cell::type::null, cell.get_data_type());
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::null));
 
-        cell = ".0e000";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value(".0e000");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = "-0.e-0";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
+        cell.set_value("-0.e-0");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
 
-        cell = "1E";
-        TS_ASSERT_EQUALS(xlnt::cell::type::string, cell.get_data_type());
+        cell.set_value("1E");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::string));
     }
 
     void test_set_bad_type()
     {
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
-
-        TS_ASSERT_THROWS(cell.set_explicit_value("ABC", xlnt::cell::type::numeric), xlnt::data_type_exception);
-        TS_ASSERT_THROWS(cell.set_explicit_value(1, xlnt::cell::type::string), xlnt::data_type_exception);
-        TS_ASSERT_THROWS(cell.set_explicit_value(1.0, xlnt::cell::type::error), xlnt::data_type_exception);
-        TS_ASSERT_THROWS(cell.set_explicit_value("3", xlnt::cell::type::boolean), xlnt::data_type_exception);
         TS_ASSERT_THROWS(cell.set_error("1"), xlnt::data_type_exception);
         TS_ASSERT_THROWS(cell.set_hyperlink("1"), xlnt::data_type_exception);
     }
@@ -328,13 +323,13 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
 
-        cell = "03:40:16";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
-        TS_ASSERT_EQUALS(cell, xlnt::time(3, 40, 16));
+        cell.set_value("03:40:16");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
+        TS_ASSERT_EQUALS(cell.get_value(), xlnt::time(3, 40, 16));
 
-        cell = "03:40";
-        TS_ASSERT_EQUALS(xlnt::cell::type::numeric, cell.get_data_type());
-        TS_ASSERT_EQUALS(cell, xlnt::time(3, 40));
+        cell.set_value("03:40");
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
+        TS_ASSERT_EQUALS(cell.get_value(), xlnt::time(3, 40));
     }
     
     void test_timedelta()
@@ -342,9 +337,9 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
         
-        cell = xlnt::timedelta(1, 3, 0, 0, 0);
-        TS_ASSERT_EQUALS(cell, 1.125);
-        TS_ASSERT_EQUALS(cell.get_data_type(), xlnt::cell::type::numeric);
+        cell.set_value(xlnt::timedelta(1, 3, 0, 0, 0));
+        TS_ASSERT_EQUALS(cell.get_value(), 1.125);
+        TS_ASSERT(cell.get_value().is(xlnt::value::type::numeric));
     }
 
     void test_date_format_on_non_date()
@@ -352,9 +347,9 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
 
-	cell = xlnt::datetime::now();
-        cell = "testme";
-        TS_ASSERT("testme" == cell);
+        cell.set_value(xlnt::datetime::now());
+        cell.set_value("testme");
+        TS_ASSERT("testme" == cell.get_value());
     }
 
     void test_set_get_date()
@@ -364,8 +359,8 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
 
-        cell = today;
-        TS_ASSERT(today == cell);
+        cell.set_value(today);
+        TS_ASSERT(today == cell.get_value());
     }
 
     void test_repr()
@@ -381,11 +376,11 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
 
-        cell = xlnt::datetime::now();
+        cell.set_value(xlnt::datetime::now());
         TS_ASSERT(cell.is_date());
 
-        cell = "testme";
-        TS_ASSERT_EQUALS("testme", cell);
+        cell.set_value("testme");
+        TS_ASSERT_EQUALS("testme", cell.get_value());
         TS_ASSERT(!cell.is_date());
     }
 
@@ -395,7 +390,7 @@ public:
         xlnt::worksheet ws = wb.create_sheet();
         xlnt::cell cell(ws, "A1");
 
-        cell = -13.5;
+        cell.set_value(-13.5);
         cell.get_style().get_number_format().set_format_code("0.00_);[Red]\\(0.00\\)");
 
         TS_ASSERT(!cell.is_date());
diff --git a/tests/test_read.hpp b/tests/test_read.hpp
index 7b45756e..22682e3a 100644
--- a/tests/test_read.hpp
+++ b/tests/test_read.hpp
@@ -22,9 +22,9 @@ public:
         TS_ASSERT_DIFFERS(ws, nullptr);
         if(!(ws == nullptr))
         {
-            TS_ASSERT_EQUALS(ws.get_cell("G5"), "hello");
-            TS_ASSERT_EQUALS(ws.get_cell("D30"), 30);
-            TS_ASSERT_EQUALS(ws.get_cell("K9"), 0.09);
+            TS_ASSERT_EQUALS(ws.get_cell("G5").get_value(), "hello");
+            TS_ASSERT_EQUALS(ws.get_cell("D30").get_value(), 30);
+            TS_ASSERT_EQUALS(ws.get_cell("K9").get_value(), 0.09);
         }
     }
     
@@ -52,10 +52,10 @@ public:
         auto wb = standard_workbook();
         auto sheet2 = wb.get_sheet_by_name("Sheet2 - Numbers");
         TS_ASSERT_DIFFERS(sheet2, nullptr);
-        TS_ASSERT_EQUALS("This is cell G5", sheet2.get_cell("G5"));
-        TS_ASSERT_EQUALS(18, sheet2.get_cell("D18"));
-        TS_ASSERT_EQUALS(true, sheet2.get_cell("G9"));
-        TS_ASSERT_EQUALS(false, sheet2.get_cell("G10"));
+        TS_ASSERT_EQUALS("This is cell G5", sheet2.get_cell("G5").get_value());
+        TS_ASSERT_EQUALS(18, sheet2.get_cell("D18").get_value());
+        TS_ASSERT_EQUALS(true, sheet2.get_cell("G9").get_value());
+        TS_ASSERT_EQUALS(false, sheet2.get_cell("G10").get_value());
     }
 
     void test_read_nostring_workbook()
@@ -179,9 +179,9 @@ public:
         auto wb_win = date_std_1900();
         auto ws_win = wb_win["Sheet1"];
         xlnt::datetime dt(2011, 10, 31);
-        TS_ASSERT_EQUALS(ws_mac.get_cell("A1"), dt);
-        TS_ASSERT_EQUALS(ws_win.get_cell("A1"), dt);
-        TS_ASSERT_EQUALS(ws_mac.get_cell("A1"), ws_win.get_cell("A1"));
+        TS_ASSERT_EQUALS(ws_mac.get_cell("A1").get_value(), dt);
+        TS_ASSERT_EQUALS(ws_win.get_cell("A1").get_value(), dt);
+        TS_ASSERT_EQUALS(ws_mac.get_cell("A1").get_value(), ws_win.get_cell("A1").get_value());
     }
     
     void test_repair_central_directory()
@@ -220,10 +220,8 @@ public:
         TS_ASSERT_EQUALS(a6.get_formula(), "SUM(A4:A5)");
     }
     
-    void test_read_complex_formulae()
+    void _test_read_complex_formulae()
     {
-        TS_SKIP("not yet implemented");
-
         /*
         auto path = PathHelper::GetDataDirectory("/reader/formulae.xlsx");
         auto wb = xlnt::reader::load_workbook(path);
@@ -287,17 +285,17 @@ public:
 
         TS_ASSERT(ws.get_formula_attributes().empty());
         TS_ASSERT(ws.get_parent().get_data_only());
-        TS_ASSERT(ws.get_cell("A2").get_data_type() == xlnt::cell::type::numeric);
-        TS_ASSERT(ws.get_cell("A2") == 12345);
+        TS_ASSERT(ws.get_cell("A2").get_value().is(xlnt::value::type::numeric));
+        TS_ASSERT(ws.get_cell("A2").get_value() == 12345);
         TS_ASSERT(!ws.get_cell("A2").has_formula());
-        TS_ASSERT(ws.get_cell("A3").get_data_type() == xlnt::cell::type::numeric);
-        TS_ASSERT(ws.get_cell("A3") == 12345);
+        TS_ASSERT(ws.get_cell("A3").get_value().is(xlnt::value::type::numeric));
+        TS_ASSERT(ws.get_cell("A3").get_value() == 12345);
         TS_ASSERT(!ws.get_cell("A3").has_formula());
-        TS_ASSERT(ws.get_cell("A4").get_data_type() == xlnt::cell::type::numeric);
-        TS_ASSERT(ws.get_cell("A4") == 24690);
+        TS_ASSERT(ws.get_cell("A4").get_value().is(xlnt::value::type::numeric));
+        TS_ASSERT(ws.get_cell("A4").get_value() == 24690);
         TS_ASSERT(!ws.get_cell("A4").has_formula());
-        TS_ASSERT(ws.get_cell("A5").get_data_type() == xlnt::cell::type::numeric);
-        TS_ASSERT(ws.get_cell("A5") == 49380);
+        TS_ASSERT(ws.get_cell("A5").get_value().is(xlnt::value::type::numeric));
+        TS_ASSERT(ws.get_cell("A5").get_value() == 49380);
         TS_ASSERT(!ws.get_cell("A5").has_formula());
     }
     
@@ -439,8 +437,8 @@ public:
     void test_guess_types()
     {
         bool guess;
-        xlnt::cell::type dtype;
-        std::vector<std::pair<bool, xlnt::cell::type>> test_cases = {{true, xlnt::cell::type::numeric}, {false, xlnt::cell::type::string}};
+        xlnt::value::type dtype;
+        std::vector<std::pair<bool, xlnt::value::type>> test_cases = {{true, xlnt::value::type::numeric}, {false, xlnt::value::type::string}};
         
         for(const auto &expected : test_cases)
         {
@@ -448,7 +446,7 @@ public:
             auto path = PathHelper::GetDataDirectory("/genuine/guess_types.xlsx");
             auto wb = xlnt::reader::load_workbook(path, guess);
             auto ws = wb.get_active_sheet();
-            TS_ASSERT_EQUALS(ws.get_cell("D2").get_data_type(), dtype);
+            TS_ASSERT(ws.get_cell("D2").get_value().is(dtype));
         }
     }
     
diff --git a/tests/test_workbook.hpp b/tests/test_workbook.hpp
index 5ea0aedc..0c53f06f 100644
--- a/tests/test_workbook.hpp
+++ b/tests/test_workbook.hpp
@@ -193,7 +193,7 @@ public:
         double float_value = 1.0 / 3.0;
         xlnt::workbook book;
         auto sheet = book.get_active_sheet();
-        sheet.get_cell("A1") = float_value;
+        sheet.get_cell("A1").set_value(float_value);
         auto dest_filename = temp_file.GetFilename();
         book.save(dest_filename);
 
@@ -201,6 +201,6 @@ public:
         test_book.load(dest_filename);
         auto test_sheet = test_book.get_active_sheet();
 
-        TS_ASSERT_LESS_THAN_EQUALS(test_sheet.get_cell("A1").get_internal_value_numeric() - float_value, 0.00001);
+        TS_ASSERT_LESS_THAN_EQUALS(test_sheet.get_cell("A1").get_value().as<double>() - float_value, 0.00001);
     }
 };
diff --git a/tests/test_worksheet.hpp b/tests/test_worksheet.hpp
index 8ab5e36f..e818850d 100644
--- a/tests/test_worksheet.hpp
+++ b/tests/test_worksheet.hpp
@@ -56,9 +56,9 @@ public:
     void test_worksheet_dimension()
     {
         xlnt::worksheet ws(wb_);
-        ws.get_cell("A1") = "AAA";
+        ws.get_cell("A1").set_value("AAA");
         TS_ASSERT_EQUALS("A1:A1", ws.calculate_dimension().to_string());
-        ws.get_cell("B12") = "AAA";
+        ws.get_cell("B12").set_value("AAA");
         TS_ASSERT_EQUALS("A1:B12", ws.calculate_dimension().to_string());
     }
 
@@ -132,9 +132,9 @@ public:
     {
         xlnt::worksheet ws(wb_);
 
-        ws.get_cell("A1").set_null();
-        ws.get_cell("B2") = "0";
-        ws.get_cell("C4") = 0;
+        ws.get_cell("A1").set_value(xlnt::value::null());
+        ws.get_cell("B2").set_value("0");
+        ws.get_cell("C4").set_value(0);
         ws.get_cell("D1").set_comment(xlnt::comment("Comment", "Comment"));
 
         ws.garbage_collect();
@@ -196,8 +196,8 @@ public:
 
         ws.append(std::vector<std::string> {"This is A1", "This is B1"});
 
-        TS_ASSERT_EQUALS("This is A1", ws.get_cell("A1"));
-        TS_ASSERT_EQUALS("This is B1", ws.get_cell("B1"));
+        TS_ASSERT_EQUALS("This is A1", ws.get_cell("A1").get_value());
+        TS_ASSERT_EQUALS("This is B1", ws.get_cell("B1").get_value());
     }
 
     void test_append_dict_letter()
@@ -206,8 +206,8 @@ public:
 
         ws.append(std::unordered_map<std::string, std::string> {{"A", "This is A1"}, {"C", "This is C1"}});
 
-        TS_ASSERT_EQUALS("This is A1", ws.get_cell("A1"));
-        TS_ASSERT_EQUALS("This is C1", ws.get_cell("C1"));
+        TS_ASSERT_EQUALS("This is A1", ws.get_cell("A1").get_value());
+        TS_ASSERT_EQUALS("This is C1", ws.get_cell("C1").get_value());
     }
 
     void test_append_dict_index()
@@ -216,8 +216,8 @@ public:
 
         ws.append(std::unordered_map<int, std::string> {{0, "This is A1"}, {2, "This is C1"}});
 
-        TS_ASSERT_EQUALS("This is A1", ws.get_cell("A1"));
-        TS_ASSERT_EQUALS("This is C1", ws.get_cell("C1"));
+        TS_ASSERT_EQUALS("This is A1", ws.get_cell("A1").get_value());
+        TS_ASSERT_EQUALS("This is C1", ws.get_cell("C1").get_value());
     }
 
     void test_append_2d_list()
@@ -229,40 +229,40 @@ public:
 
         auto vals = ws.get_range("A1:B2");
 
-        TS_ASSERT_EQUALS(vals[0][0], "This is A1");
-        TS_ASSERT_EQUALS(vals[0][1], "This is B1");
-        TS_ASSERT_EQUALS(vals[1][0], "This is A2");
-        TS_ASSERT_EQUALS(vals[1][1], "This is B2");
+        TS_ASSERT_EQUALS(vals[0][0].get_value(), "This is A1");
+        TS_ASSERT_EQUALS(vals[0][1].get_value(), "This is B1");
+        TS_ASSERT_EQUALS(vals[1][0].get_value(), "This is A2");
+        TS_ASSERT_EQUALS(vals[1][1].get_value(), "This is B2");
     }
 
     void test_rows()
     {
         xlnt::worksheet ws(wb_);
 
-        ws.get_cell("A1") = "first";
-        ws.get_cell("C9") = "last";
+        ws.get_cell("A1").set_value("first");
+        ws.get_cell("C9").set_value("last");
 
         auto rows = ws.rows();
 
         TS_ASSERT_EQUALS(rows.length(), 9);
 
-        TS_ASSERT_EQUALS(rows[0][0], "first");
-        TS_ASSERT_EQUALS(rows[8][2], "last");
+        TS_ASSERT_EQUALS(rows[0][0].get_value(), "first");
+        TS_ASSERT_EQUALS(rows[8][2].get_value(), "last");
     }
     
     void test_cols()
     {
         xlnt::worksheet ws(wb_);
 
-        ws.get_cell("A1") = "first";
-        ws.get_cell("C9") = "last";
+        ws.get_cell("A1").set_value("first");
+        ws.get_cell("C9").set_value("last");
 
         auto cols = ws.columns();
 
         TS_ASSERT_EQUALS(cols.length(), 3);
 
-        TS_ASSERT_EQUALS(cols[0][0], "first");
-        TS_ASSERT_EQUALS(cols[2][8], "last");
+        TS_ASSERT_EQUALS(cols[0][0].get_value(), "first");
+        TS_ASSERT_EQUALS(cols[2][8].get_value(), "last");
     }
 
     void test_auto_filter()
@@ -298,44 +298,184 @@ public:
 
     void test_write_empty()
     {
-    	TS_SKIP("not implemented");
-    	
         xlnt::worksheet ws(wb_);
         
         auto xml_string = xlnt::writer::write_worksheet(ws);
 
         pugi::xml_document doc;
         doc.load(xml_string.c_str());
+
+        auto expected_string = 
+        "<worksheet xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\" xmlns:r=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships\">"
+        "  <sheetPr>"
+        "    <outlinePr summaryRight=\"1\" summaryBelow=\"1\"/>"
+        "  </sheetPr>"
+        "  <dimension ref=\"A1:A1\"/>"
+        "  <sheetViews>"
+        "    <sheetView workbookViewId=\"0\">"
+        "      <selection sqref=\"A1\" activeCell=\"A1\"/>"
+        "    </sheetView>"
+        "  </sheetViews>"
+        "  <sheetFormatPr baseColWidth=\"10\" defaultRowHeight=\"15\"/>"
+        "  <sheetData/>"
+        "  <pageMargins left=\"0.75\" right=\"0.75\" top=\"1\" bottom=\"1\" header=\"0.5\" footer=\"0.5\"/>"
+        "</worksheet>";
+
+        pugi::xml_document expected_doc;
+        expected_doc.load(expected_string);
+
+        TS_ASSERT(Helper::compare_xml(expected_doc, doc));
     }
     
     void test_page_margins()
     {
-        TS_SKIP("not implemented");
-    	
         xlnt::worksheet ws(wb_);
+
+        ws.get_page_margins().set_left(2);
+        ws.get_page_margins().set_right(2);
+        ws.get_page_margins().set_top(2);
+        ws.get_page_margins().set_bottom(2);
+        ws.get_page_margins().set_header(1.5);
+        ws.get_page_margins().set_footer(1.5);
         
         auto xml_string = xlnt::writer::write_worksheet(ws);
 
         pugi::xml_document doc;
         doc.load(xml_string.c_str());
+
+        auto expected_string = 
+        "<worksheet xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\" xmlns:r=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships\">"
+        "  <sheetPr>"
+        "    <outlinePr summaryRight=\"1\" summaryBelow=\"1\"/>"
+        "  </sheetPr>"
+        "  <dimension ref=\"A1:A1\"/>"
+        "  <sheetViews>"
+        "    <sheetView workbookViewId=\"0\">"
+        "      <selection sqref=\"A1\" activeCell=\"A1\"/>"
+        "    </sheetView>"
+        "  </sheetViews>"
+        "  <sheetFormatPr baseColWidth=\"10\" defaultRowHeight=\"15\"/>"
+        "  <sheetData/>"
+        "  <pageMargins left=\"2\" right=\"2\" top=\"2\" bottom=\"2\" header=\"1.5\" footer=\"1.5\"/>"
+        "</worksheet>";
+
+        pugi::xml_document expected_doc;
+        expected_doc.load(expected_string);
+
+        TS_ASSERT(Helper::compare_xml(expected_doc, doc));
     }
    
     void test_merge()
     {
-        TS_SKIP("not implemented");
-    	
         xlnt::worksheet ws(wb_);
+        std::vector<std::string> string_table = {"Cell A1", "Cell B1"};
         
-        auto xml_string = xlnt::writer::write_worksheet(ws);
+        auto expected_string1 = 
+        "<worksheet xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\" xmlns:r=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships\">"
+        "  <sheetPr>"
+        "    <outlinePr summaryRight=\"1\" summaryBelow=\"1\"/>"
+        "  </sheetPr>"
+        "  <dimension ref=\"A1:B1\"/>"
+        "  <sheetViews>"
+        "    <sheetView workbookViewId=\"0\">"
+        "      <selection sqref=\"A1\" activeCell=\"A1\"/>"
+        "    </sheetView>"
+        "  </sheetViews>"
+        "  <sheetFormatPr baseColWidth=\"10\" defaultRowHeight=\"15\"/>"
+        "  <sheetData>"
+        "    <row r=\"1\" spans=\"1:2\">"
+        "      <c r=\"A1\" t=\"s\">"
+        "        <v>0</v>"
+        "      </c>"
+        "      <c r=\"B1\" t=\"s\">"
+        "        <v>1</v>"
+        "      </c>"
+        "    </row>"
+        "  </sheetData>"
+        "  <pageMargins left=\"0.75\" right=\"0.75\" top=\"1\" bottom=\"1\" header=\"0.5\" footer=\"0.5\"/>"
+        "</worksheet>";
+
+        ws.get_cell("A1").set_value("Cell A1");
+        ws.get_cell("B1").set_value("Cell B1");
+
+        auto xml_string = xlnt::writer::write_worksheet(ws, string_table);
 
         pugi::xml_document doc;
         doc.load(xml_string.c_str());
+
+        pugi::xml_document expected_doc;
+        expected_doc.load(expected_string1);
+
+        TS_ASSERT(Helper::compare_xml(expected_doc, doc));
+
+        ws.merge_cells("A1:B1");
+        xml_string = xlnt::writer::write_worksheet(ws, string_table);
+
+        auto expected_string2 = 
+        "<worksheet xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\" xmlns:r=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships\">"
+        "  <sheetPr>"
+        "    <outlinePr summaryRight=\"1\" summaryBelow=\"1\"/>"
+        "  </sheetPr>"
+        "  <dimension ref=\"A1:B1\"/>"
+        "  <sheetViews>"
+        "    <sheetView workbookViewId=\"0\">"
+        "      <selection sqref=\"A1\" activeCell=\"A1\"/>"
+        "    </sheetView>"
+        "  </sheetViews>"
+        "  <sheetFormatPr baseColWidth=\"10\" defaultRowHeight=\"15\"/>"
+        "  <sheetData>"
+        "    <row r=\"1\" spans=\"1:2\">"
+        "      <c r=\"A1\" t=\"s\">"
+        "        <v>0</v>"
+        "      </c>"
+        "      <c r=\"B1\" t=\"s\"/>"
+        "    </row>"
+        "  </sheetData>"
+        " <mergeCells count=\"1\">"
+        "    <mergeCell ref=\"A1:B1\"/>"
+        "  </mergeCells>"
+        "  <pageMargins left=\"0.75\" right=\"0.75\" top=\"1\" bottom=\"1\" header=\"0.5\" footer=\"0.5\"/>"
+        "</worksheet>";
+
+        doc.load(xml_string.c_str());
+        expected_doc.load(expected_string2);
+
+        TS_ASSERT(Helper::compare_xml(expected_doc, doc));
+
+        ws.unmerge_cells("A1:B1");
+        xml_string = xlnt::writer::write_worksheet(ws, string_table);
+
+        auto expected_string3 = 
+        "<worksheet xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\" xmlns:r=\"http://schemas.openxmlformats.org/officeDocument/2006/relationships\">"
+        "  <sheetPr>"
+        "    <outlinePr summaryRight=\"1\" summaryBelow=\"1\"/>"
+        "  </sheetPr>"
+        "  <dimension ref=\"A1:B1\"/>"
+        "  <sheetViews>"
+        "    <sheetView workbookViewId=\"0\">"
+        "      <selection sqref=\"A1\" activeCell=\"A1\"/>"
+        "    </sheetView>"
+        "  </sheetViews>"
+        "  <sheetFormatPr baseColWidth=\"10\" defaultRowHeight=\"15\"/>"
+        "  <sheetData>"
+        "    <row r=\"1\" spans=\"1:2\">"
+        "      <c r=\"A1\" t=\"s\">"
+        "        <v>0</v>"
+        "      </c>"
+        "      <c r=\"B1\" t=\"s\"/>"
+        "    </row>"
+        "  </sheetData>"
+        "  <pageMargins left=\"0.75\" right=\"0.75\" top=\"1\" bottom=\"1\" header=\"0.5\" footer=\"0.5\"/>"
+        "</worksheet>";
+
+        doc.load(xml_string.c_str());
+        expected_doc.load(expected_string3);
+
+        TS_ASSERT(Helper::compare_xml(expected_doc, doc));
     }
 
     void test_printer_settings()
     {
-        TS_SKIP("not implemented");
-    	
         xlnt::worksheet ws(wb_);
 
         ws.get_page_setup().set_orientation(xlnt::page_setup::orientation::landscape);
@@ -433,45 +573,35 @@ public:
     
     void test_positioning_point()
     {
-        TS_SKIP("not implemented");
-        /*
         auto ws = wb_.create_sheet();
-         */
+        TS_ASSERT_EQUALS(ws.get_point_pos(150, 40), xlnt::cell_reference("C3"));
     }
     
     void test_positioning_roundtrip()
     {
-        TS_SKIP("not implemented");
-        /*
     	auto ws = wb_.create_sheet();
     	TS_ASSERT_EQUALS(ws.get_point_pos(ws.get_cell("A1").get_anchor()), xlnt::cell_reference("A1"));
-    	TS_ASSERT_EQUALS(ws.get_point_pos(ws.get_cell("D52").get_anchor()), xlnt::cell_reference("D52"));
-    	TS_ASSERT_EQUALS(ws.get_point_pos(ws.get_cell("X11").get_anchor()), xlnt::cell_reference("X11"));
-         */
+        TS_ASSERT_EQUALS(ws.get_point_pos(ws.get_cell("D52").get_anchor()), xlnt::cell_reference("D52"));
+        TS_ASSERT_EQUALS(ws.get_point_pos(ws.get_cell("X11").get_anchor()), xlnt::cell_reference("X11"));
     }
     
     void test_page_setup()
     {
-        TS_SKIP("not implemented");
-        /*
     	xlnt::page_setup p;
-    	TS_ASSERT(p.get_page_setup().empty());
-    	p.set_scale(1);
-    	TS_ASSERT_EQUALS(p.get_page_setup().at("scale"), 1);
-         */
+    	TS_ASSERT_EQUALS(p.get_scale(), 1);
+    	p.set_scale(2);
+    	TS_ASSERT_EQUALS(p.get_scale(), 2);
     }
     
     void test_page_options()
     {
-        TS_SKIP("not implemented");
-        /*
     	xlnt::page_setup p;
-    	TS_ASSERT(p.get_options().empty());
+    	TS_ASSERT(!p.get_horizontal_centered());
+        TS_ASSERT(!p.get_vertical_centered());
     	p.set_horizontal_centered(true);
     	p.set_vertical_centered(true);
-    	TS_ASSERT_EQUALS(p.get_options().at("verticalCentered"), "1");
-    	TS_ASSERT_EQUALS(p.get_options().at("horizontalCentered"), "1");
-         */
+        TS_ASSERT(p.get_horizontal_centered());
+        TS_ASSERT(p.get_vertical_centered());
     }
 
 private:
diff --git a/tests/test_write.hpp b/tests/test_write.hpp
index bc57aff6..dfb131b0 100644
--- a/tests/test_write.hpp
+++ b/tests/test_write.hpp
@@ -58,7 +58,7 @@ public:
     void test_write_worksheet()
     {
 		auto ws = wb_.create_sheet();
-        ws.get_cell("F42") = "hello";
+        ws.get_cell("F42").set_value("hello");
         auto content = xlnt::writer::write_worksheet(ws, {"hello"}, {});
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1.xml", content));
     }
@@ -67,25 +67,25 @@ public:
     {
 		auto ws = wb_.create_sheet();
         ws.get_page_setup().set_sheet_state(xlnt::page_setup::sheet_state::hidden);
-        ws.get_cell("F42") = "hello";
+        ws.get_cell("F42").set_value("hello");
         auto content = xlnt::writer::write_worksheet(ws, {"hello"}, {});
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1.xml", content));
     }
 
     void test_write_bool()
     {
-		auto ws = wb_.create_sheet();
-        ws.get_cell("F42") = false;
-        ws.get_cell("F43") = true;
+        auto ws = wb_.create_sheet();
+        ws.get_cell("F42").set_value(false);
+        ws.get_cell("F43").set_value(true);
         auto content = xlnt::writer::write_worksheet(ws, {}, {});
-	TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_bool.xml", content));
+        TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_bool.xml", content));
     }
 
     void test_write_formula()
     {
 		auto ws = wb_.create_sheet();
-        ws.get_cell("F1") = 10;
-        ws.get_cell("F2") = 32;
+        ws.get_cell("F1").set_value(10);
+        ws.get_cell("F2").set_value(32);
         ws.get_cell("F3").set_formula("F1+F2");
         auto content = xlnt::writer::write_worksheet(ws, {}, {});
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_formula.xml", content));
@@ -96,7 +96,7 @@ public:
         xlnt::workbook wb_guess_types;
         wb_guess_types.set_guess_types(true);
 		auto ws = wb_guess_types.create_sheet();
-        ws.get_cell("F1") = "13%";
+        ws.get_cell("F1").set_value("13%");
 		auto style_id_by_hash = xlnt::style_writer(wb_guess_types).get_style_by_hash();
         auto content = xlnt::writer::write_worksheet(ws, {}, style_id_by_hash);
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_style.xml", content));
@@ -105,7 +105,7 @@ public:
     void test_write_height()
     {
 		auto ws = wb_.create_sheet();
-        ws.get_cell("F1") = 10;
+        ws.get_cell("F1").set_value(10);
         ws.get_row_properties(ws.get_cell("F1").get_row()).set_height(30);
         auto content = xlnt::writer::write_worksheet(ws, {}, {});
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_height.xml", content));
@@ -114,7 +114,7 @@ public:
     void test_write_hyperlink()
     {
 		auto ws = wb_.create_sheet();
-        ws.get_cell("A1") = "test";
+        ws.get_cell("A1").set_value("test");
         ws.get_cell("A1").set_hyperlink("http://test.com");
         auto content = xlnt::writer::write_worksheet(ws, {"test"}, {});
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_hyperlink.xml", content));
@@ -124,10 +124,10 @@ public:
     {
 		auto ws = wb_.create_sheet();
         TS_ASSERT_EQUALS(0, ws.get_relationships().size());
-        ws.get_cell("A1") = "test";
+        ws.get_cell("A1").set_value("test");
         ws.get_cell("A1").set_hyperlink("http://test.com/");
         TS_ASSERT_EQUALS(1, ws.get_relationships().size());
-        ws.get_cell("A2") = "test";
+        ws.get_cell("A2").set_value("test");
         ws.get_cell("A2").set_hyperlink("http://test2.com/");
         TS_ASSERT_EQUALS(2, ws.get_relationships().size());
         auto content = xlnt::writer::write_worksheet_rels(ws);
@@ -138,16 +138,16 @@ public:
     {
 		auto ws = wb_.create_sheet();
         ws.get_cell("A1").set_hyperlink("http://test.com");
-        TS_ASSERT_EQUALS("http://test.com", ws.get_cell("A1"));
-        ws.get_cell("A1") = "test";
-        TS_ASSERT_EQUALS("test", ws.get_cell("A1"));
+        TS_ASSERT_EQUALS("http://test.com", ws.get_cell("A1").get_value());
+        ws.get_cell("A1").set_value("test");
+        TS_ASSERT_EQUALS("test", ws.get_cell("A1").get_value());
     }
 
     void test_write_auto_filter()
     {
         xlnt::workbook wb;
         auto ws = wb.get_sheet_by_index(0);
-        ws.get_cell("F42") = "hello";
+        ws.get_cell("F42").set_value("hello");
         ws.auto_filter("A1:F1");
         auto content = xlnt::writer::write_worksheet(ws, {"hello"}, {});
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_auto_filter.xml", content));
@@ -158,17 +158,17 @@ public:
 
     void test_freeze_panes_horiz()
     {
-		auto ws = wb_.create_sheet();
-        ws.get_cell("F42") = "hello";
+        auto ws = wb_.create_sheet();
+        ws.get_cell("F42").set_value("hello");
         ws.freeze_panes("A4");
         auto content = xlnt::writer::write_worksheet(ws, {"hello"}, {});
-	TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_freeze_panes_horiz.xml", content));
+        TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_freeze_panes_horiz.xml", content));
     }
 
     void test_freeze_panes_vert()
     {
 		auto ws = wb_.create_sheet();
-        ws.get_cell("F42") = "hello";
+        ws.get_cell("F42").set_value("hello");
         ws.freeze_panes("D1");
         auto content = xlnt::writer::write_worksheet(ws, {"hello"}, {});
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_freeze_panes_vert.xml", content));
@@ -177,7 +177,7 @@ public:
     void test_freeze_panes_both()
     {
 		auto ws = wb_.create_sheet();
-        ws.get_cell("F42") = "hello";
+        ws.get_cell("F42").set_value("hello");
         ws.freeze_panes("D4");
         auto content = xlnt::writer::write_worksheet(ws, {"hello"}, {});
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/sheet1_freeze_panes_both.xml", content));
@@ -186,7 +186,7 @@ public:
     void test_long_number()
     {
 		auto ws = wb_.create_sheet();
-        ws.get_cell("A1") = 9781231231230;
+        ws.get_cell("A1").set_value(9781231231230);
         auto content = xlnt::writer::write_worksheet(ws, {}, {});
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/long_number.xml", content));
     }
@@ -194,7 +194,7 @@ public:
     void test_short_number()
     {
 		auto ws = wb_.create_sheet();
-        ws.get_cell("A1") = 1234567890;
+        ws.get_cell("A1").set_value(1234567890);
         auto content = xlnt::writer::write_worksheet(ws, {}, {});
         TS_ASSERT(Helper::EqualsFileContent(PathHelper::GetDataDirectory() + "/writer/expected/short_number.xml", content));
     }