fork download
copy 
  1. #include <iostream>
  2. #include <iomanip>
  3. #include <utility>
  4. #include <type_traits>
  5.  
  6.  
  7. template<typename...>
  8. struct void_type {
  9.  
  10.    using type = void;	
  11. };
  12.  
  13. template<typename ...T>
  14. using void_t = typename void_type<T...>::type;
  15.  
  16.  
  17. template<typename T, typename = void>
  18. struct is_invokable_with_member_function_foo : std::false_type {};
  19.  
  20. template<typename T, typename ...Args>
  21. struct is_invokable_with_member_function_foo<
  22.       T (Args...)
  23.     , void_t<decltype(std::declval<T>().foo(std::declval<Args>()...))>
  24. > : std::true_type {};
  25.  
  26.  
  27. struct A {};
  28.  
  29. struct B {
  30.  
  31.    void foo();
  32.    void foo(int, double);
  33. };
  34.  
  35. struct C {
  36.    void foo(int);
  37.    void foo(int, double) const;
  38. };
  39.  
  40.  
  41. int main() {
  42. 	std::cout << std::boolalpha;
  43. 	std::cout << "A::foo() -> "
  44. 	          << is_invokable_with_member_function_foo<A ()>()
  45. 	          << std::endl;
  46. 	std::cout << "B::foo() -> "
  47. 	          << is_invokable_with_member_function_foo<B ()>()
  48. 	          << std::endl;
  49. 	std::cout << "B::foo(int) -> "
  50. 	          << is_invokable_with_member_function_foo<B (int)>()
  51. 	          << std::endl;
  52. 	std::cout << "B::foo(int, double) -> "
  53. 	          << is_invokable_with_member_function_foo<B (int, double)>()
  54. 	          << std::endl;
  55. 	std::cout << "B::foo(char, int) -> "
  56. 	          << is_invokable_with_member_function_foo<B (char, int)>()
  57. 	          << std::endl;
  58. 	std::cout << "B::foo(int, double) const -> "
  59. 	          << is_invokable_with_member_function_foo<B const (int, double)>()
  60. 	          << std::endl;
  61. 	std::cout << "C::foo(int) -> "
  62. 	          << is_invokable_with_member_function_foo<C (int)>()
  63. 	          << std::endl;
  64. 	std::cout << "C::foo(int, double) -> "
  65. 	          << is_invokable_with_member_function_foo<C (int, double)>()
  66. 	          << std::endl;
  67. 	std::cout << "C::foo(int, double) const -> "
  68. 	          << is_invokable_with_member_function_foo<C const (int, double)>()
  69. 	          << std::endl;
  70. }
  71.  
Success #stdin #stdout 0s 3456KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
A::foo() -> false
B::foo() -> true
B::foo(int) -> false
B::foo(int, double) -> true
B::foo(char, int) -> true
B::foo(int, double) const -> false
C::foo(int) -> true
C::foo(int, double) -> true
C::foo(int, double) const -> true
https://ideone.com/hzRM78
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!