| //===----------------------------------------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is dual licensed under the MIT and the University of Illinois Open |
| // Source Licenses. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| // <functional> |
| |
| // template<Returnable R, CopyConstructible... ArgTypes> |
| // class function<R(ArgTypes...)> { |
| // public: |
| // typedef R result_type; |
| // typedef T1 argument_type; // iff sizeof...(ArgTypes) == 1 and |
| // // the type in ArgTypes is T1 |
| // typedef T1 first_argument_type; // iff sizeof...(ArgTypes) == 2 and |
| // // ArgTypes contains T1 and T2 |
| // typedef T2 second_argument_type; // iff sizeof...(ArgTypes) == 2 and |
| // // ArgTypes contains T1 and T2 |
| // ... |
| // }; |
| |
| #include <functional> |
| #include <type_traits> |
| |
| |
| template <typename T> |
| class has_argument_type |
| { |
| typedef char yes; |
| typedef long no; |
| |
| template <typename C> static yes check( typename C::argument_type * ); |
| template <typename C> static no check(...); |
| public: |
| enum { value = sizeof(check<T>(0)) == sizeof(yes) }; |
| }; |
| |
| template <typename T> |
| class has_first_argument_type |
| { |
| typedef char yes; |
| typedef long no; |
| |
| template <typename C> static yes check( typename C::first_argument_type * ); |
| template <typename C> static no check(...); |
| public: |
| enum { value = sizeof(check<T>(0)) == sizeof(yes) }; |
| }; |
| |
| |
| template <typename T> |
| class has_second_argument_type |
| { |
| typedef char yes; |
| typedef long no; |
| |
| template <typename C> static yes check( typename C::second_argument_type *); |
| template <typename C> static no check(...); |
| public: |
| enum { value = sizeof(check<T>(0)) == sizeof(yes) }; |
| }; |
| |
| template <class F, class return_type> |
| void test_nullary_function () |
| { |
| static_assert((std::is_same<typename F::result_type, return_type>::value), "" ); |
| static_assert((!has_argument_type<F>::value), "" ); |
| static_assert((!has_first_argument_type<F>::value), "" ); |
| static_assert((!has_second_argument_type<F>::value), "" ); |
| } |
| |
| template <class F, class return_type, class arg_type> |
| void test_unary_function () |
| { |
| static_assert((std::is_same<typename F::result_type, return_type>::value), "" ); |
| static_assert((std::is_same<typename F::argument_type, arg_type>::value), "" ); |
| static_assert((!has_first_argument_type<F>::value), "" ); |
| static_assert((!has_second_argument_type<F>::value), "" ); |
| } |
| |
| template <class F, class return_type, class arg_type1, class arg_type2> |
| void test_binary_function () |
| { |
| static_assert((std::is_same<typename F::result_type, return_type>::value), "" ); |
| static_assert((std::is_same<typename F::first_argument_type, arg_type1>::value), "" ); |
| static_assert((std::is_same<typename F::second_argument_type, arg_type2>::value), "" ); |
| static_assert((!has_argument_type<F>::value), "" ); |
| } |
| |
| template <class F, class return_type> |
| void test_other_function () |
| { |
| static_assert((std::is_same<typename F::result_type, return_type>::value), "" ); |
| static_assert((!has_argument_type<F>::value), "" ); |
| static_assert((!has_first_argument_type<F>::value), "" ); |
| static_assert((!has_second_argument_type<F>::value), "" ); |
| } |
| |
| int main() |
| { |
| test_nullary_function<std::function<int()>, int>(); |
| test_unary_function <std::function<double(int)>, double, int>(); |
| test_binary_function <std::function<double(int, char)>, double, int, char>(); |
| test_other_function <std::function<double(int, char, double)>, double>(); |
| } |