ChaiScript/include/chaiscript/dispatchkit/function_call_detail.hpp
2018-05-30 08:30:29 -06:00

116 lines
3.8 KiB
C++

// This file is distributed under the BSD License.
// See "license.txt" for details.
// Copyright 2009-2012, Jonathan Turner (jonathan@emptycrate.com)
// Copyright 2009-2018, Jason Turner (jason@emptycrate.com)
// http://www.chaiscript.com
// This is an open source non-commercial project. Dear PVS-Studio, please check it.
// PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
#ifndef CHAISCRIPT_FUNCTION_CALL_DETAIL_HPP_
#define CHAISCRIPT_FUNCTION_CALL_DETAIL_HPP_
#include <functional>
#include <memory>
#include <string>
#include <type_traits>
#include <vector>
#include "boxed_cast.hpp"
#include "boxed_number.hpp"
#include "boxed_value.hpp"
#include "type_conversions.hpp"
#include "proxy_functions.hpp"
namespace chaiscript
{
namespace dispatch
{
namespace detail
{
/// used internally for unwrapping a function call's types
template<typename Ret, typename ... Param>
struct Build_Function_Caller_Helper
{
Build_Function_Caller_Helper(std::vector<Const_Proxy_Function> t_funcs, const Type_Conversions *t_conversions)
: m_funcs(std::move(t_funcs)),
m_conversions(t_conversions)
{
}
Ret call(const Function_Params &params, const Type_Conversions_State &t_state)
{
if constexpr (std::is_arithmetic_v<Ret>) {
return Boxed_Number(dispatch::dispatch(m_funcs, params, t_state)).get_as<Ret>();
} else if constexpr (std::is_same_v<void, Ret>) {
dispatch::dispatch(m_funcs, params, t_state);
} else {
return boxed_cast<Ret>(dispatch::dispatch(m_funcs, params, t_state), &t_state);
}
}
template<typename ... P>
Ret operator()(P&& ... param)
{
std::array<Boxed_Value, sizeof...(P)> params{box<P>(std::forward<P>(param))...};
if (m_conversions) {
Type_Conversions_State state(*m_conversions, m_conversions->conversion_saves());
return call(Function_Params{params}, state);
} else {
Type_Conversions conv;
Type_Conversions_State state(conv, conv.conversion_saves());
return call(Function_Params{params}, state);
}
}
template<typename P, typename Q>
static Boxed_Value box(Q &&q) {
if constexpr (std::is_same_v<chaiscript::Boxed_Value, std::decay_t<Q>>) {
return std::forward<Q>(q);
} else if constexpr (std::is_reference_v<P>) {
return Boxed_Value(std::ref(std::forward<Q>(q)));
} else {
return Boxed_Value(std::forward<Q>(q));
}
}
std::vector<Const_Proxy_Function> m_funcs;
const Type_Conversions *m_conversions;
};
/// \todo what happens if t_conversions is deleted out from under us?!
template<typename Ret, typename ... Params>
std::function<Ret (Params...)> build_function_caller_helper(Ret (Params...), const std::vector<Const_Proxy_Function> &funcs, const Type_Conversions_State *t_conversions)
{
/*
if (funcs.size() == 1)
{
std::shared_ptr<const Proxy_Function_Impl<Ret (Params...)>> pfi =
std::dynamic_pointer_cast<const Proxy_Function_Impl<Ret (Params...)> >
(funcs[0]);
if (pfi)
{
return pfi->internal_function();
}
// looks like this either wasn't a Proxy_Function_Impl or the types didn't match
// we cannot make any other guesses or assumptions really, so continuing
}
*/
return std::function<Ret (Params...)>(Build_Function_Caller_Helper<Ret, Params...>(funcs, t_conversions?t_conversions->get():nullptr));
}
}
}
}
#endif