[C++] explicit

개요

• 암시적 변환 방지

예제

• 코드

   #include <string>
      
   using namespace std;
      
   class Test1 {
   	private:
   		int i;
      
   	public:
   		Test1(int i){};
   		Test1(string s){};
   		~Test1(){};
   };
      
   class Test2 {
   	private:
   		int i;
      
   	public:
   		explicit Test2(int i){};
   		Test2(string s){};
   		~Test2(){};
   };
      
   void func1(Test1 t) {}
   void func2(Test2 t) {}
      
   int main() {
   	func1(Test1(1));
   	func1(1);
      
   	func2(Test2(2));
   	func2(2);
      
   	return 0;
   }
  

• 실행 결과

   test.cpp: In function ‘int main()’:
   test.cpp:33:15: error: could not convert ‘2’ from ‘int’ to ‘Test2’
      33 |         func2(2);
         |               ^
         |               |
         |               int