Re: [boost] Re: win32.hpp and min/max macros

From: John Maddock (john_at_[hidden])
Date: 2004-01-03 07:44:05

> No. I'm including 2 programs, one for which including <algorithm> does
> *not* remove the ambiguity, and one for which the inclusion of win32.hpp
> silently changes the meaning of the program. This fooling with the
> min/max macros simply has to go.
>
> //
> // inclusion of win32.hpp silently changes the meaning of a program
> //
> #include <iostream>
> using std::cout;
> using std::endl;
>
> #include <windows.h>
>
> void foo()
> {
>      unsigned long i = 1;
>      signed long j = -1;
>      cout << max(i,j) << endl;
>      cout << typeid(max(i,j)).name() << endl;
>      cout << endl;
> }
>
> #include <algorithm>
> #include <boost/utility.hpp>
>
> void bar()
> {
>      unsigned long i = 1;
>      signed long j = -1;
>      cout << max(i,j) << endl;
>      cout << typeid(max(i,j)).name() << endl;
>      cout << endl;
> }
>
> int main()
> {
>      foo();
>      bar();
>      return 0;
> }
>
> Output:
>
> 4294967295
> unsigned long
>
> 1
> long

I have to admit I'm amazed by the behaviour of the macro versions here -
they may be std conforming, but in what way are these correct?  All the more
reason to regard signed/unsigned comparisons as errors IMO.  Anyway, you are
correct, this change in behaviour is unacceptable, lets get the release out
the way, and then address this properly.

John.