Re: Using assignment operator when rhs is temporary object.

I have found a difference in behavior of a Borland C++ compiler and Visual
C++ 2005 EE compiler.

class A
{
public:
    A( int i = 0 ): a( i ) {}
    A( A &rhs ): a( rhs.a ) {}
    virtual ~A(){}
    A & operator=( A &rhs ) // without const!
    {
        if ( this != &rhs )
        {
            a = rhs.a;
        }

        return ( *this );
    }

    virtual std::ostream & out( std::ostream &os ) const
    {
        os << a;
        return ( os );
    }

private:
    int a;
};

inline std::ostream & operator<<( std::ostream &os, const A &rhs )
{
    return ( rhs.out( os ) );
}

A f()
{
    return ( A( 5 ) );
}

int _tmain(int argc, _TCHAR* argv[])
{
    A a1( 10 );
    A a2;

    a2 = f();

    return 0;
}

For the Borland C++ compliker the compilation is failed as the compiler does
not find a required function for the assignment statement a2 = f();
because the assignment operator has no attribute const for rhs parameter
while Visual C++ compiles the code without any error.

Which compiler is wrong according to the C++ standard?