vectorwrapper/include/vectorwrapper/has_method.hpp

55 lines
2 KiB
C++

/*
* Copyright 2015 Michele "King_DuckZ" Santullo
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef idFBC29C5127784D35BE62F7BAC16E3687
#define idFBC29C5127784D35BE62F7BAC16E3687
#define define_has_method(method_name,pretty_name) \
template <typename T> \
struct Has ## pretty_name ## Method { \
private: \
struct TrueType { int a[2]; }; \
typedef int FalseType; \
template <typename C> static TrueType has_method ( decltype(&C::method_name) ); \
template <typename C> static FalseType has_method ( ... ); \
public: \
enum { value = sizeof(has_method<T>(0)) == sizeof(TrueType) }; \
}
#define define_has_typedef(typedef_name,pretty_name) \
template <typename T> \
struct Has ## pretty_name ## Typedef { \
private: \
struct TrueType { int a[2]; }; \
typedef int FalseType; \
template <typename C> static decltype(C::typedef_name(), TrueType()) has_typedef ( int ); \
template <typename C> static FalseType has_typedef ( ... ); \
public: \
enum { value = sizeof(has_typedef<T>(0)) == sizeof(TrueType) }; \
}
#define define_has_enum(enum_name,pretty_name) \
template <typename T> \
struct Has ## pretty_name ## Enum { \
private: \
struct TrueType { int a[2]; }; \
typedef int FalseType; \
template <int> void f ( void ); \
template <typename C> static TrueType has_enum ( decltype(&f<C::enum_name>) = nullptr ); \
template <typename C> static FalseType has_enum ( ... ); \
public:\
enum { value = sizeof(has_enum<T>(nullptr)) == sizeof(TrueType) }; \
}
#endif