Microsoft KB Archive/140604

= FIX: 'using' Declaration Doesn't Overload Base Class Members =

Article ID: 140604

Article Last Modified on 7/5/2005

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APPLIES TO


 * Microsoft Visual C++ 4.0 Standard Edition
 * Microsoft Visual C++ 4.1 Subscription
 * Microsoft Visual C++ 4.2 Enterprise Edition
 * Microsoft Visual C++ 5.0 Enterprise Edition
 * Microsoft Visual C++ 6.0 Enterprise Edition
 * Microsoft Visual C++ 4.2 Professional Edition
 * Microsoft Visual C++ 5.0 Professional Edition
 * Microsoft Visual C++ 6.0 Professional Edition
 * Microsoft Visual C++ 6.0 Standard Edition

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This article was previously published under Q140604



SYMPTOMS
Attempting to overload member functions located in a base class from a derived class with a 'using' declaration, may result in the following compiler error:

error C2664: 'function': cannot convert parameter 'number' from 'type1' to 'type2'



CAUSE
This particular problem occurs if the member functions that are being overloaded are declared before the 'using' declaration in the class definition.



RESOLUTION
Place the 'using' declaration above the declarations for the member functions you want to overload. See the comments in the following code sample:

Sample Code

 * 1) include "iostream.h"

class A { public: int f(int) {cout << "In A::f(int)!!!\n";return 0;} };

class B : public A { public: int f(char*){cout << "In D::f(char*)!!!\n";return 0;} using A::f;       // <<== move this above the int f(char*) // declaration to fix the problem. };

void main {  B d;   d.A::f(1); d.f(1);           // <<== C2664 happens here d.f("Hi There"); }



STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.

This problem was corrected in Microsoft Visual C++ .NET.

