sol2/sol/traits.hpp
ThePhD e69e7c79fa C++17 additions: std::variant, string_views of all types, checker for if we have the right version
added variadic_results, to return a variable number of arguments to Lua
added variadic_results and as_results
added improved function examples (for multiple results and split overloading out)
added tests for variadics
added tests for C++17 utilities
added a forwarding header
added a specific `unsafe_function` header
added and improved documetation pages
2017-07-09 12:54:52 -04:00

510 lines
16 KiB
C++

// The MIT License (MIT)
// Copyright (c) 2013-2017 Rapptz, ThePhD and contributors
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#ifndef SOL_TRAITS_HPP
#define SOL_TRAITS_HPP
#include "tuple.hpp"
#include "bind_traits.hpp"
#include <type_traits>
#include <memory>
#include <functional>
#include <iterator>
#ifdef SOL_CXX17_FEATURES
#include <string_view>
#endif
namespace sol {
template<std::size_t I>
using index_value = std::integral_constant<std::size_t, I>;
namespace meta {
template<typename T>
struct identity { typedef T type; };
template<typename T>
using identity_t = typename identity<T>::type;
template<typename... Args>
struct is_tuple : std::false_type { };
template<typename... Args>
struct is_tuple<std::tuple<Args...>> : std::true_type { };
template <typename T>
struct is_builtin_type : std::integral_constant<bool, std::is_arithmetic<T>::value || std::is_pointer<T>::value || std::is_array<T>::value> {};
template<typename T>
struct unwrapped {
typedef T type;
};
template<typename T>
struct unwrapped<std::reference_wrapper<T>> {
typedef T type;
};
template<typename T>
using unwrapped_t = typename unwrapped<T>::type;
template <typename T>
struct unwrap_unqualified : unwrapped<unqualified_t<T>> {};
template <typename T>
using unwrap_unqualified_t = typename unwrap_unqualified<T>::type;
template<typename T>
struct remove_member_pointer;
template<typename R, typename T>
struct remove_member_pointer<R T::*> {
typedef R type;
};
template<typename R, typename T>
struct remove_member_pointer<R T::* const> {
typedef R type;
};
template<typename T>
using remove_member_pointer_t = remove_member_pointer<T>;
template<template<typename...> class Templ, typename T>
struct is_specialization_of : std::false_type { };
template<typename... T, template<typename...> class Templ>
struct is_specialization_of<Templ, Templ<T...>> : std::true_type { };
template<class T, class...>
struct all_same : std::true_type { };
template<class T, class U, class... Args>
struct all_same<T, U, Args...> : std::integral_constant <bool, std::is_same<T, U>::value && all_same<T, Args...>::value> { };
template<class T, class...>
struct any_same : std::false_type { };
template<class T, class U, class... Args>
struct any_same<T, U, Args...> : std::integral_constant <bool, std::is_same<T, U>::value || any_same<T, Args...>::value> { };
template<typename T>
using invoke_t = typename T::type;
template<bool B>
using boolean = std::integral_constant<bool, B>;
template<typename T>
using neg = boolean<!T::value>;
template<typename Condition, typename Then, typename Else>
using condition = std::conditional_t<Condition::value, Then, Else>;
template<typename... Args>
struct all : boolean<true> {};
template<typename T, typename... Args>
struct all<T, Args...> : condition<T, all<Args...>, boolean<false>> {};
template<typename... Args>
struct any : boolean<false> {};
template<typename T, typename... Args>
struct any<T, Args...> : condition<T, boolean<true>, any<Args...>> {};
enum class enable_t {
_
};
constexpr const auto enabler = enable_t::_;
template<bool value, typename T = void>
using disable_if_t = std::enable_if_t<!value, T>;
template<typename... Args>
using enable = std::enable_if_t<all<Args...>::value, enable_t>;
template<typename... Args>
using disable = std::enable_if_t<neg<all<Args...>>::value, enable_t>;
template<typename... Args>
using disable_any = std::enable_if_t<neg<any<Args...>>::value, enable_t>;
template<typename V, typename... Vs>
struct find_in_pack_v : boolean<false> { };
template<typename V, typename Vs1, typename... Vs>
struct find_in_pack_v<V, Vs1, Vs...> : any<boolean<(V::value == Vs1::value)>, find_in_pack_v<V, Vs...>> { };
namespace meta_detail {
template<std::size_t I, typename T, typename... Args>
struct index_in_pack : std::integral_constant<std::size_t, SIZE_MAX> { };
template<std::size_t I, typename T, typename T1, typename... Args>
struct index_in_pack<I, T, T1, Args...> : std::conditional_t<std::is_same<T, T1>::value, std::integral_constant<std::ptrdiff_t, I>, index_in_pack<I + 1, T, Args...>> { };
}
template<typename T, typename... Args>
struct index_in_pack : meta_detail::index_in_pack<0, T, Args...> { };
template<typename T, typename List>
struct index_in : meta_detail::index_in_pack<0, T, List> { };
template<typename T, typename... Args>
struct index_in<T, types<Args...>> : meta_detail::index_in_pack<0, T, Args...> { };
template<std::size_t I, typename... Args>
struct at_in_pack {};
template<std::size_t I, typename... Args>
using at_in_pack_t = typename at_in_pack<I, Args...>::type;
template<std::size_t I, typename Arg, typename... Args>
struct at_in_pack<I, Arg, Args...> : std::conditional<I == 0, Arg, at_in_pack_t<I - 1, Args...>> {};
template<typename Arg, typename... Args>
struct at_in_pack<0, Arg, Args...> { typedef Arg type; };
namespace meta_detail {
template<std::size_t Limit, std::size_t I, template<typename...> class Pred, typename... Ts>
struct count_for_pack : std::integral_constant<std::size_t, 0> {};
template<std::size_t Limit, std::size_t I, template<typename...> class Pred, typename T, typename... Ts>
struct count_for_pack<Limit, I, Pred, T, Ts...> : std::conditional_t < sizeof...(Ts) == 0 || Limit < 2,
std::integral_constant<std::size_t, I + static_cast<std::size_t>(Limit != 0 && Pred<T>::value)>,
count_for_pack<Limit - 1, I + static_cast<std::size_t>(Pred<T>::value), Pred, Ts...>
> { };
template<std::size_t I, template<typename...> class Pred, typename... Ts>
struct count_2_for_pack : std::integral_constant<std::size_t, 0> {};
template<std::size_t I, template<typename...> class Pred, typename T, typename U, typename... Ts>
struct count_2_for_pack<I, Pred, T, U, Ts...> : std::conditional_t<sizeof...(Ts) == 0,
std::integral_constant<std::size_t, I + static_cast<std::size_t>(Pred<T>::value)>,
count_2_for_pack<I + static_cast<std::size_t>(Pred<T>::value), Pred, Ts...>
> { };
} // meta_detail
template<template<typename...> class Pred, typename... Ts>
struct count_for_pack : meta_detail::count_for_pack<sizeof...(Ts), 0, Pred, Ts...> { };
template<template<typename...> class Pred, typename List>
struct count_for;
template<template<typename...> class Pred, typename... Args>
struct count_for<Pred, types<Args...>> : count_for_pack<Pred, Args...> {};
template<std::size_t Limit, template<typename...> class Pred, typename... Ts>
struct count_for_to_pack : meta_detail::count_for_pack<Limit, 0, Pred, Ts...> { };
template<template<typename...> class Pred, typename... Ts>
struct count_2_for_pack : meta_detail::count_2_for_pack<0, Pred, Ts...> { };
template<typename... Args>
struct return_type {
typedef std::tuple<Args...> type;
};
template<typename T>
struct return_type<T> {
typedef T type;
};
template<>
struct return_type<> {
typedef void type;
};
template <typename... Args>
using return_type_t = typename return_type<Args...>::type;
namespace meta_detail {
template <typename> struct always_true : std::true_type {};
struct is_invokable_tester {
template <typename Fun, typename... Args>
always_true<decltype(std::declval<Fun>()(std::declval<Args>()...))> static test(int);
template <typename...>
std::false_type static test(...);
};
} // meta_detail
template <typename T>
struct is_invokable;
template <typename Fun, typename... Args>
struct is_invokable<Fun(Args...)> : decltype(meta_detail::is_invokable_tester::test<Fun, Args...>(0)) {};
namespace meta_detail {
template<typename T, bool isclass = std::is_class<unqualified_t<T>>::value>
struct is_callable : std::is_function<std::remove_pointer_t<T>> {};
template<typename T>
struct is_callable<T, true> {
using yes = char;
using no = struct { char s[2]; };
struct F { void operator()(); };
struct Derived : T, F {};
template<typename U, U> struct Check;
template<typename V>
static no test(Check<void (F::*)(), &V::operator()>*);
template<typename>
static yes test(...);
static const bool value = sizeof(test<Derived>(0)) == sizeof(yes);
};
struct has_begin_end_impl {
template<typename T, typename U = unqualified_t<T>,
typename B = decltype(std::declval<U&>().begin()),
typename E = decltype(std::declval<U&>().end())>
static std::true_type test(int);
template<typename...>
static std::false_type test(...);
};
struct has_key_type_impl {
template<typename T, typename U = unqualified_t<T>,
typename V = typename U::key_type>
static std::true_type test(int);
template<typename...>
static std::false_type test(...);
};
struct has_mapped_type_impl {
template<typename T, typename U = unqualified_t<T>,
typename V = typename U::mapped_type>
static std::true_type test(int);
template<typename...>
static std::false_type test(...);
};
struct has_value_type_impl {
template<typename T, typename U = unqualified_t<T>,
typename V = typename U::value_type>
static std::true_type test(int);
template<typename...>
static std::false_type test(...);
};
struct has_iterator_impl {
template<typename T, typename U = unqualified_t<T>,
typename V = typename U::iterator>
static std::true_type test(int);
template<typename...>
static std::false_type test(...);
};
struct has_key_value_pair_impl {
template<typename T, typename U = unqualified_t<T>,
typename V = typename U::value_type,
typename F = decltype(std::declval<V&>().first),
typename S = decltype(std::declval<V&>().second)>
static std::true_type test(int);
template<typename...>
static std::false_type test(...);
};
template <typename T, typename U = T, typename = decltype(std::declval<T&>() < std::declval<U&>())>
std::true_type supports_op_less_test(const T&);
std::false_type supports_op_less_test(...);
template <typename T, typename U = T, typename = decltype(std::declval<T&>() == std::declval<U&>())>
std::true_type supports_op_equal_test(const T&);
std::false_type supports_op_equal_test(...);
template <typename T, typename U = T, typename = decltype(std::declval<T&>() <= std::declval<U&>())>
std::true_type supports_op_less_equal_test(const T&);
std::false_type supports_op_less_equal_test(...);
} // meta_detail
template <typename T>
using supports_op_less = decltype(meta_detail::supports_op_less_test(std::declval<T&>()));
template <typename T>
using supports_op_equal = decltype(meta_detail::supports_op_equal_test(std::declval<T&>()));
template <typename T>
using supports_op_less_equal = decltype(meta_detail::supports_op_less_equal_test(std::declval<T&>()));
template<typename T>
struct is_callable : boolean<meta_detail::is_callable<T>::value> {};
template<typename T>
struct has_begin_end : decltype(meta_detail::has_begin_end_impl::test<T>(0)) {};
template<typename T>
struct has_key_value_pair : decltype(meta_detail::has_key_value_pair_impl::test<T>(0)) {};
template<typename T>
struct has_key_type : decltype(meta_detail::has_key_type_impl::test<T>(0)) {};
template<typename T>
struct has_mapped_type : decltype(meta_detail::has_mapped_type_impl::test<T>(0)) {};
template<typename T>
struct has_iterator : decltype(meta_detail::has_iterator_impl::test<T>(0)) {};
template<typename T>
struct has_value_type : decltype(meta_detail::has_value_type_impl::test<T>(0)) {};
template <typename T>
struct is_associative : meta::all<has_key_value_pair<T>, has_mapped_type<T>> {};
template <typename T>
using is_string_constructible = any<
std::is_same<unqualified_t<T>, const char*>
, std::is_same<unqualified_t<T>, char>
, std::is_same<unqualified_t<T>, std::string>
, std::is_same<unqualified_t<T>, std::initializer_list<char>>
#ifdef SOL_CXX17_FEATURES
, std::is_same<unqualified_t<T>, std::string_view>
#endif
>;
template <typename T>
struct is_pair : std::false_type {};
template <typename T1, typename T2>
struct is_pair<std::pair<T1, T2>> : std::true_type {};
template <typename T>
using is_c_str = any<
std::is_same<std::decay_t<unqualified_t<T>>, const char*>,
std::is_same<std::decay_t<unqualified_t<T>>, char*>,
std::is_same<unqualified_t<T>, std::string>
>;
template <typename T>
struct is_move_only : all<
neg<std::is_reference<T>>,
neg<std::is_copy_constructible<unqualified_t<T>>>,
std::is_move_constructible<unqualified_t<T>>
> {};
template <typename T>
using is_not_move_only = neg<is_move_only<T>>;
namespace meta_detail {
template <typename T, meta::disable<meta::is_specialization_of<std::tuple, meta::unqualified_t<T>>> = meta::enabler>
decltype(auto) force_tuple(T&& x) {
return std::forward_as_tuple(std::forward<T>(x));
}
template <typename T, meta::enable<meta::is_specialization_of<std::tuple, meta::unqualified_t<T>>> = meta::enabler>
decltype(auto) force_tuple(T&& x) {
return std::forward<T>(x);
}
} // meta_detail
template <typename... X>
decltype(auto) tuplefy(X&&... x) {
return std::tuple_cat(meta_detail::force_tuple(std::forward<X>(x))...);
}
template <typename T, typename = void>
struct iterator_tag {
using type = std::input_iterator_tag;
};
template <typename T>
struct iterator_tag<T, std::conditional_t<false, typename T::iterator_category, void>> {
using type = typename T::iterator_category;
};
} // meta
namespace detail {
template <std::size_t I, typename Tuple>
decltype(auto) forward_get(Tuple&& tuple) {
return std::forward<meta::tuple_element_t<I, Tuple>>(std::get<I>(tuple));
}
template <std::size_t... I, typename Tuple>
auto forward_tuple_impl(std::index_sequence<I...>, Tuple&& tuple) -> decltype(std::tuple<decltype(forward_get<I>(tuple))...>(forward_get<I>(tuple)...)) {
return std::tuple<decltype(forward_get<I>(tuple))...>(std::move(std::get<I>(tuple))...);
}
template <typename Tuple>
auto forward_tuple(Tuple&& tuple) {
auto x = forward_tuple_impl(std::make_index_sequence<std::tuple_size<meta::unqualified_t<Tuple>>::value>(), std::forward<Tuple>(tuple));
return x;
}
template<typename T>
auto unwrap(T&& item) -> decltype(std::forward<T>(item)) {
return std::forward<T>(item);
}
template<typename T>
T& unwrap(std::reference_wrapper<T> arg) {
return arg.get();
}
template<typename T>
auto deref(T&& item) -> decltype(std::forward<T>(item)) {
return std::forward<T>(item);
}
template<typename T>
inline T& deref(T* item) {
return *item;
}
template<typename T, typename Dx>
inline std::add_lvalue_reference_t<T> deref(std::unique_ptr<T, Dx>& item) {
return *item;
}
template<typename T>
inline std::add_lvalue_reference_t<T> deref(std::shared_ptr<T>& item) {
return *item;
}
template<typename T, typename Dx>
inline std::add_lvalue_reference_t<T> deref(const std::unique_ptr<T, Dx>& item) {
return *item;
}
template<typename T>
inline std::add_lvalue_reference_t<T> deref(const std::shared_ptr<T>& item) {
return *item;
}
template<typename T>
inline T* ptr(T& val) {
return std::addressof(val);
}
template<typename T>
inline T* ptr(std::reference_wrapper<T> val) {
return std::addressof(val.get());
}
template<typename T>
inline T* ptr(T* val) {
return val;
}
} // detail
} // sol
#endif // SOL_TRAITS_HPP