Magic_Game/src/kiwano/core/function.hpp

354 lines
8.0 KiB
C++

// Copyright (c) 2016-2018 Kiwano - Nomango
//
// 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.
#pragma once
#include <stdexcept>
#include <type_traits>
namespace kiwano
{
inline namespace core
{
//
// function is a light weight ::std::function<>-like class
//
namespace __function_detail
{
//
// is_callable
//
namespace __callable_detail
{
template <typename _Ty, typename _Ret, typename... _Args>
struct helper
{
template <typename _Uty> static int test(...);
template <typename _Uty, _Ret(_Uty::*)(_Args...)> struct class_mem;
template <typename _Uty> static char test(class_mem<_Uty, &_Uty::operator()>*);
template <typename _Uty, _Ret(_Uty::*)(_Args...) const> struct class_const_mem;
template <typename _Uty> static char test(class_const_mem<_Uty, &_Uty::operator()>*);
template<
typename _Uty,
typename _Uret = typename ::std::decay<decltype(::std::declval<_Uty>().operator()(::std::declval<_Args>()...))>::type,
typename = typename ::std::enable_if<::std::is_convertible<_Ret, _Uret>::value>::type>
static char test(int);
static constexpr bool value = sizeof(test<_Ty>(0)) == sizeof(char);
};
}
template<typename _Ty, typename _Ret, typename... _Args>
struct is_callable
: public ::std::bool_constant<__callable_detail::helper<_Ty, _Ret, _Args...>::value>
{
};
//
// callable
//
template<typename _Ret, typename... _Args>
class callable
{
public:
virtual ~callable() {}
virtual void retain() = 0;
virtual void release() = 0;
virtual _Ret invoke(_Args... args) const = 0;
};
template<typename _Ret, typename... _Args>
class ref_count_callable
: public callable<_Ret, _Args...>
{
public:
ref_count_callable() : ref_count_(0) {}
virtual void retain() override
{
++ref_count_;
}
virtual void release() override
{
--ref_count_;
if (ref_count_ <= 0)
{
delete this;
}
}
private:
int ref_count_;
};
template<typename _Ty, typename _Ret, typename... _Args>
class proxy_callable
: public ref_count_callable<_Ret, _Args...>
{
public:
proxy_callable(_Ty&& val)
: callee_(::std::move(val))
{
}
virtual _Ret invoke(_Args... args) const override
{
return callee_(::std::forward<_Args&&>(args)...);
}
static inline callable<_Ret, _Args...>* make(_Ty&& val)
{
return new (::std::nothrow) proxy_callable<_Ty, _Ret, _Args...>(::std::move(val));
}
private:
_Ty callee_;
};
template<typename _Ty, typename _Ret, typename... _Args>
class proxy_mem_callable
: public ref_count_callable<_Ret, _Args...>
{
public:
typedef _Ret(_Ty::* _FuncType)(_Args...);
virtual _Ret invoke(_Args... args) const override
{
return (static_cast<_Ty*>(ptr_)->*func_)(::std::forward<_Args>(args)...);
}
static inline callable<_Ret, _Args...>* make(void* ptr, _FuncType func)
{
return new (::std::nothrow) proxy_mem_callable<_Ty, _Ret, _Args...>(ptr, func);
}
protected:
proxy_mem_callable(void* ptr, _FuncType func)
: ptr_(ptr)
, func_(func)
{
}
protected:
void* ptr_;
_FuncType func_;
};
template<typename _Ty, typename _Ret, typename... _Args>
class proxy_const_mem_callable
: public ref_count_callable<_Ret, _Args...>
{
public:
typedef _Ret(_Ty::* _FuncType)(_Args...) const;
virtual _Ret invoke(_Args... args) const override
{
return (static_cast<_Ty*>(ptr_)->*func_)(::std::forward<_Args>(args)...);
}
static inline callable<_Ret, _Args...>* make(void* ptr, _FuncType func)
{
return new (::std::nothrow) proxy_const_mem_callable<_Ty, _Ret, _Args...>(ptr, func);
}
protected:
proxy_const_mem_callable(void* ptr, _FuncType func)
: ptr_(ptr)
, func_(func)
{
}
protected:
void* ptr_;
_FuncType func_;
};
}
//
// exceptions
//
class bad_function_call : public ::std::exception
{
public:
bad_function_call() {}
virtual const char* what() const override
{
return "bad function call";
}
};
//
// function details
//
template<typename _Ty>
class function;
template<typename _Ret, typename... _Args>
class function<_Ret(_Args...)>
{
public:
function()
: callable_(nullptr)
{
}
function(std::nullptr_t)
: callable_(nullptr)
{
}
function(const function& rhs)
: callable_(rhs.callable_)
{
if (callable_) callable_->retain();
}
function(function&& rhs) noexcept
: callable_(rhs.callable_)
{
rhs.callable_ = nullptr;
}
function(_Ret(*func)(_Args...))
{
callable_ = __function_detail::proxy_callable<_Ret(*)(_Args...), _Ret, _Args...>::make(::std::move(func));
if (callable_) callable_->retain();
}
template<
typename _Ty,
typename = typename ::std::enable_if<__function_detail::is_callable<_Ty, _Ret, _Args...>::value, int>::type>
function(_Ty val)
{
callable_ = __function_detail::proxy_callable<_Ty, _Ret, _Args...>::make(::std::move(val));
if (callable_) callable_->retain();
}
template<typename _Ty,
typename _Uty,
typename = typename ::std::enable_if<::std::is_same<_Ty, _Uty>::value || ::std::is_base_of<_Ty, _Uty>::value, int>::type>
function(_Uty* ptr, _Ret(_Ty::* func)(_Args...))
{
callable_ = __function_detail::proxy_mem_callable<_Ty, _Ret, _Args...>::make(ptr, func);
if (callable_) callable_->retain();
}
template<typename _Ty,
typename _Uty,
typename = typename ::std::enable_if<::std::is_same<_Ty, _Uty>::value || ::std::is_base_of<_Ty, _Uty>::value, int>::type>
function(_Uty* ptr, _Ret(_Ty::* func)(_Args...) const)
{
callable_ = __function_detail::proxy_const_mem_callable<_Ty, _Ret, _Args...>::make(ptr, func);
if (callable_) callable_->retain();
}
~function()
{
tidy();
}
inline void swap(const function& rhs)
{
::std::swap(callable_, rhs.callable_);
}
inline _Ret operator()(_Args... args) const
{
if (!callable_)
throw bad_function_call();
return callable_->invoke(::std::forward<_Args>(args)...);
}
inline operator bool() const
{
return !!callable_;
}
inline function& operator=(const function& rhs)
{
tidy();
callable_ = rhs.callable_;
if (callable_) callable_->retain();
return (*this);
}
inline function& operator=(function&& rhs)
{
tidy();
callable_ = rhs.callable_;
rhs.callable_ = nullptr;
return (*this);
}
private:
inline void tidy()
{
if (callable_)
{
callable_->release();
callable_ = nullptr;
}
}
private:
__function_detail::callable<_Ret, _Args...>* callable_;
};
} // inline namespace core
} // namespace kiwano
namespace kiwano
{
template<typename _Ty,
typename _Uty,
typename = typename std::enable_if<
std::is_same<_Ty, _Uty>::value || std::is_base_of<_Ty, _Uty>::value, int
>::type,
typename _Ret,
typename... _Args>
inline function<_Ret(_Args...)> Closure(_Uty* ptr, _Ret(_Ty::* func)(_Args...))
{
return function<_Ret(_Args...)>(ptr, func);
}
template<typename _Ty,
typename _Uty,
typename = typename std::enable_if<
std::is_same<_Ty, _Uty>::value || std::is_base_of<_Ty, _Uty>::value, int
>::type,
typename _Ret,
typename... _Args>
inline function<_Ret(_Args...)> Closure(_Uty* ptr, _Ret(_Ty::* func)(_Args...) const)
{
return function<_Ret(_Args...)>(ptr, func);
}
}