Compiler Warning (level 4) C4510


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The latest version of this topic can be found at Compiler Warning (level 4) C4510.

class' : default constructor could not be generated

The compiler cannot generate a default constructor for the specified class and no user-defined constructor was created. You will not be able to create objects of this type.

There are several situations that prevent the compiler from generating a default constructor, including:

  • A const data member.

  • A data member that is a reference.

You need to create a user-defined default constructor for the class that initializes these members.

The following sample generates C4510:

// C4510.cpp  
// compile with: /W4  
struct A {  
   const int i;  
   int &j;  
   A& operator=( const A& ); // C4510 expected  
   // uncomment the following line to resolve this C4510  
   // A(int ii, int &jj) : i(ii), j(jj) {}  
};   // C4510  
int main() {