Question

In Visual Studio 2008, the following code will build successfully:

void Foo (int x);//Prototype

void Foo(const int x)//Implementation
{

}

However, this will generate an error (unresolved external symbol) during linking:

void Foo (int x);//Prototype

void Foo(const int x)//Implementation
{

}

void Bar()
{
    int x = 0;
    Foo(x);
}

The problem is because the function implementation for Foo specifies that the integer argument is constant, while the prototype does not require a constant.

Why does this happen? How come the problem isn’t detected during compilation?

Answer 1

It’s because you have a broken compiler. Broken compilers can choose their behavior themselfs. I know some compilers have this broken handling of that case.

Look on MSDN about a manual that documents that broken behavior. It works fine with compliant (non-broken in this regard) compilers.