Re: preprocessor seems interfering namespace defines?

wenmang@yahoo.com wrote:


Right. the problem is the macro max(), which conflicts with the member
function with the same name (the algorithm max has the same problem, but
it sounds like you haven't hit that one yet).

Under Windows, the solution is to define _NO_MINMAX (or something like
that, it's been a while) before including the offending files. If there
isn't a mechanism like that for the file that's messing up your code,
one approach would be to start every list of include files with:

    #include "share.h"
    #undef max

That way you'll blow away the macro before it does any damage to headers
that aren't prepared for it. On the other hand, it might cause problems
for other headers from the same package that assume that the macro
definition is still there. If that's the case, one possibility (NOT
TESTED) would be:

    #include "share.h"
    #undef max
    #include <algorithm>
    using std::max;

That kills the macro, but puts the C++ algorithm named max in the global
namespace, where subsequent headers will see it. I wouldn't do this
automatically, only if it's needed to solve actual problems. It may well
be that the macro max is only used in the library's source files, so all
you need to do is get rid of it.

Another approach, if you don't mind doing a little surgery on your
compiler's headers, is to find all their uses of max and replace them
with (max) (i.e. put parentheses around them). The preprocessor won't
treat a name as a function-like macro if it's not followed by a left
parenthesis, so it won't mess with those uses of max. You'll have to do
the same in your source code if you use max:

    return (max)(a, b);

--

    -- Pete
Roundhouse Consulting, Ltd. (www.versatilecoding.com)
Author of "The Standard C++ Library Extensions: a Tutorial and
Reference." (www.petebecker.com/tr1book)