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  1. #include <cstdint>
  2.  
  3. #define DEFINE_HAS_SIGNATURE(traitsName, funcName, signature)               \
  4.     template <typename U>                                                   \
  5.     class traitsName                                                        \
  6.     {                                                                       \
  7.     private:                                                                \
  8.         template<typename T, T> struct helper;                              \
  9.         template<typename T>                                                \
  10.         static std::uint8_t check(helper<signature, &funcName>*);           \
  11.         template<typename T> static std::uint16_t check(...);               \
  12.     public:                                                                 \
  13.         static                                                              \
  14.         constexpr bool value = sizeof(check<U>(0)) == sizeof(std::uint8_t); \
  15.     }
  16.  
  17. DEFINE_HAS_SIGNATURE(has_static_foo, T::foo, void (*)(void)); // signature is the important part for static. it is not (T::*)
  18.  
  19. class StaticFoo
  20. {
  21. public:
  22.     static void foo();
  23. };
  24.  
  25. class Foo
  26. {
  27. public:
  28.     void foo();
  29. };
  30.  
  31. class Bar
  32. {
  33. };
  34.  
  35. static_assert(has_static_foo<StaticFoo>::value, "");
  36. static_assert(!has_static_foo<Foo>::value, "");
  37. static_assert(!has_static_foo<Bar>::value, "");
  38.  
  39. int main()
  40. {}
  41.  
Success #stdin #stdout 0s 3136KB
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https://ideone.com/1gkcYn
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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