sol2/sol/function.hpp
ThePhD 37c3883eb6 Free functions and lambdas whos first arguments match the userdata type (unqualified)
now are usable as functions for userdata.
allows free functions and lambdas to provide useful operations, like operator+*-/
and other things which may not be implemented as class members.
2014-08-09 04:54:58 -07:00

262 lines
10 KiB
C++

// The MIT License (MIT)
// Copyright (c) 2013 Danny Y., Rapptz
// 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_FUNCTION_HPP
#define SOL_FUNCTION_HPP
#include "reference.hpp"
#include "tuple.hpp"
#include "stack.hpp"
#include "function_types.hpp"
#include "userdata_traits.hpp"
#include "resolve.hpp"
#include <cstdint>
#include <functional>
#include <memory>
namespace sol {
class function : public reference {
private:
void luacall (std::size_t argcount, std::size_t resultcount) const {
lua_call(state(), static_cast<uint32_t>(argcount), static_cast<uint32_t>(resultcount));
}
template<typename... Ret>
std::tuple<Ret...> invoke(types<Ret...>, std::size_t n) const {
luacall(n, sizeof...(Ret));
return stack::pop_reverse_call(state(), std::make_tuple<Ret...>, types<Ret...>());
}
template<typename Ret>
Ret invoke(types<Ret>, std::size_t n) const {
luacall(n, 1);
return stack::pop<Ret>(state());
}
void invoke(types<void>, std::size_t n) const {
luacall(n, 0);
}
void invoke(types<>, std::size_t n) const {
luacall(n, 0);
}
public:
function() : reference() {}
function(lua_State* L, int index = -1): reference(L, index) {
type_assert(L, index, type::function);
}
function(const function&) = default;
function& operator=(const function&) = default;
template<typename... Args>
void operator()(Args&&... args) const {
call<>(std::forward<Args>(args)...);
}
template<typename... Ret, typename... Args>
typename return_type<Ret...>::type operator()(types<Ret...>, Args&&... args) const {
return call<Ret...>(std::forward<Args>(args)...);
}
template<typename... Ret, typename... Args>
typename return_type<Ret...>::type call(Args&&... args) const {
push();
stack::push_args(state(), std::forward<Args>(args)...);
return invoke(types<Ret...>(), sizeof...(Args));
}
};
namespace stack {
template<typename... Sigs>
struct pusher<function_sig_t<Sigs...>> {
template<typename R, typename... Args, typename Fx, typename = typename std::result_of<Fx(Args...)>::type>
static void set_memfx(types<R(Args...)> t, lua_State* L, Fx&& fx) {
typedef Decay<Unwrap<Fx>> raw_fx_t;
typedef R(* fx_ptr_t)(Args...);
typedef std::is_convertible<raw_fx_t, fx_ptr_t> is_convertible;
set_isconvertible_fx(is_convertible(), t, L, std::forward<Fx>(fx));
}
template<typename... Args, typename Fx, typename R = typename std::result_of<Fx(Args...)>::type>
static void set_memfx(types<Args...>, lua_State* L, Fx&& fx){
set_memfx(types<R(Args...)>(), L, std::forward<Fx>(fx));
}
template<typename Fx>
static void set_memfx(types<>, lua_State* L, Fx&& fx) {
typedef Unqualified<Unwrap<Fx>> fx_t;
typedef decltype(&fx_t::operator()) Sig;
set_memfx(types<function_signature_t<Sig>>(), L, std::forward<Fx>(fx));
}
template<typename... Args, typename R>
static void set(lua_State* L, R fxptr(Args...)){
set_fx(std::false_type(), L, fxptr);
}
template<typename Sig>
static void set(lua_State* L, Sig* fxptr){
set_fx(std::false_type(), L, fxptr);
}
template<typename... Args, typename R, typename C, typename T>
static void set(lua_State* L, R (C::*memfxptr)(Args...), T&& obj) {
typedef Bool<is_specialization_of<T, std::reference_wrapper>::value || std::is_pointer<T>::value> is_reference;
set_reference_fx(is_reference(), L, memfxptr, std::forward<T>(obj));
}
template<typename Sig, typename C, typename T>
static void set(lua_State* L, Sig C::* memfxptr, T&& obj) {
typedef Bool<is_specialization_of<T, std::reference_wrapper>::value || std::is_pointer<T>::value> is_reference;
set_reference_fx(is_reference(), L, memfxptr, std::forward<T>(obj));
}
template<typename... Sig, typename Fx>
static void set(lua_State* L, Fx&& fx) {
set_memfx(types<Sig...>(), L, std::forward<Fx>(fx));
}
template<typename Fx, typename R, typename... Args>
static void set_isconvertible_fx(std::true_type, types<R(Args...)>, lua_State* L, Fx&& fx) {
typedef R(* fx_ptr_t)(Args...);
fx_ptr_t fxptr = unwrapper(std::forward<Fx>(fx));
set(L, fxptr);
}
template<typename Fx, typename R, typename... Args>
static void set_isconvertible_fx(std::false_type, types<R(Args...)>, lua_State* L, Fx&& fx) {
typedef Decay<Unwrap<Fx>> fx_t;
std::unique_ptr<base_function> sptr(new functor_function<fx_t>(std::forward<Fx>(fx)));
set_fx<Fx>(L, std::move(sptr));
}
template<typename Fx, typename T>
static void set_reference_fx(std::true_type, lua_State* L, Fx&& fx, T&& obj) {
set_fx(std::true_type(), L, std::forward<Fx>(fx), std::forward<T>(obj));
}
template<typename Fx, typename T>
static void set_reference_fx(std::false_type, lua_State* L, Fx&& fx, T&& obj) {
typedef typename std::remove_pointer<Decay<Fx>>::type clean_fx;
std::unique_ptr<base_function> sptr(new member_function<clean_fx, T>(std::forward<T>(obj), std::forward<Fx>(fx)));
return set_fx<Fx>(L, std::move(sptr));
}
template<typename Fx, typename T>
static void set_fx(std::true_type, lua_State* L, Fx&& fx, T&& obj) {
// Layout:
// idx 1...n: verbatim data of member function pointer
// idx n + 1: is the object's void pointer
// We don't need to store the size, because the other side is templated
// with the same member function pointer type
Decay<Fx> memfxptr(std::forward<Fx>(fx));
auto userptr = sol::detail::get_ptr(obj);
void* userobjdata = static_cast<void*>(userptr);
lua_CFunction freefunc = &static_member_function<Decay<decltype(*userptr)>, Fx>::call;
int upvalues = stack::detail::push_as_upvalues(L, memfxptr);
stack::push(L, userobjdata);
++upvalues;
stack::push(L, freefunc, upvalues);
}
template<typename Fx>
static void set_fx(std::false_type, lua_State* L, Fx&& fx) {
Decay<Fx> target(std::forward<Fx>(fx));
lua_CFunction freefunc = &static_function<Fx>::call;
int upvalues = stack::detail::push_as_upvalues(L, target);
stack::push(L, freefunc, upvalues);
}
template<typename Fx>
static void set_fx(lua_State* L, std::unique_ptr<base_function> luafunc) {
auto&& metakey = userdata_traits<Unqualified<Fx>>::metatable;
const char* metatablename = std::addressof(metakey[0]);
base_function* target = luafunc.release();
void* userdata = reinterpret_cast<void*>(target);
lua_CFunction freefunc = &base_function::call;
if (luaL_newmetatable(L, metatablename) == 1) {
lua_pushstring(L, "__gc");
stack::push(L, &base_function::gc);
lua_settable(L, -3);
lua_pop(L, 1);
}
stack::detail::push_userdata<void*>(L, metatablename, userdata);
stack::push(L, freefunc, 1);
}
template<typename... Args>
static void push(lua_State* L, Args&&... args) {
set(L, std::forward<Args>(args)...);
}
};
template<typename Signature>
struct pusher<std::function<Signature>> {
static void push(lua_State* L, std::function<Signature> fx) {
pusher<function_t>{}.push(L, std::move(fx));
}
};
template<typename Signature>
struct getter<std::function<Signature>> {
typedef function_traits<Signature> fx_t;
typedef typename fx_t::args_type args_t;
typedef typename tuple_types<typename fx_t::return_type>::type ret_t;
template<typename... FxArgs, typename... Ret>
static std::function<Signature> get_std_func(types<FxArgs...>, types<Ret...>, lua_State* L, int index = -1) {
typedef typename function_traits<Signature>::return_type return_t;
sol::function f(L, index);
auto fx = [ f, L, index ] (FxArgs&&... args) -> return_t {
return f(types<Ret...>(), std::forward<FxArgs>(args)...);
};
return std::move(fx);
}
template<typename... FxArgs>
static std::function<Signature> get_std_func(types<FxArgs...>, types<void>, lua_State* L, int index = -1) {
sol::function f(L, index);
auto fx = [ f, L, index ] (FxArgs&&... args) -> void {
f(std::forward<FxArgs>(args)...);
};
return std::move(fx);
}
template<typename... FxArgs>
static std::function<Signature> get_std_func(types<FxArgs...> t, types<>, lua_State* L, int index = -1) {
return get_std_func(std::move(t), types<void>(), L, index);
}
static std::function<Signature> get(lua_State* L, int index) {
return get_std_func(args_t(), ret_t(), L, index);
}
};
} // stack
} // sol
#endif // SOL_FUNCTION_HPP