[C++] is_invocable

개요

• 호출 가능 여부 확인

예제

• 코드

   #include <iostream>
   #include <string>
   #include <type_traits>
      
   using namespace std;
      
   class A {
   	public:
   		string func(int i) { return "a"; }
   };
      
   auto func(int i) { return "a"; };
      
   int main() {
   	cout << is_invocable<decltype(func), int>::value << endl;
   	cout << is_invocable<decltype(func), string>::value << endl;
   	cout << is_invocable_r<string, decltype(func), int>::value << endl;
   	cout << is_invocable_r<string, decltype(func), string>::value << endl;
      
   	cout << "------" << endl;
      
   	cout << is_invocable<decltype(&A::func), A, int>::value << endl;
   	cout << is_invocable<decltype(&A::func), A, string>::value << endl;
   	cout << is_invocable_r<string, decltype(&A::func), A, int>::value << endl;
   	cout << is_invocable_r<string, decltype(&A::func), A, string>::value
   		 << endl;
      
   	return 0;
   }
  

• 실행 결과

   1
   0
   1
   0
   ------
   1
   0
   1
   0