Why max (max(a,b), c) is error

Question

Reference: code snippet from C++ Template: The Complete Guide

// maximum of two values of any type (call-by-reference) 
template  
inline T         


        

Answer 1

The problem is that the C-string flavor of max returns by value, not so much that it takes its arguments by value. The generic 3-way max function is declared to return a reference but the C-string max returns a value, which would then result in returning a reference to a temporary that will be dead before you can access it.

Update: The new code you added is not equivalent to your original problem. This would:

const int*& fReturnValue(const int *i)
{
    return i;
}

Note that fReturnValue returns a reference to the local variable i, whose lifetime ends by the time the function returns. So the function returns a reference to an invalid object. Try to compile your code with that change, you should get a warning from pretty much every compiler.