Re: libstdc++/5133: Problems with toupper

[Martin Sebor <sebor@roguewave.com>]

The following reply was made to PR libstdc++/5133; it has been noted by GNATS.

From: Martin Sebor <sebor@roguewave.com>
To: Pete Ratzlaff <rpete@legs.harvard.edu>
Cc: gcc-gnats@gcc.gnu.org
Subject: Re: libstdc++/5133: Problems with toupper
Date: Sun, 17 Nov 2002 19:27:09 -0700

 Pete Ratzlaff wrote:
 ...
 > 
 > All I can guess is that Martin was thinking of the std::ptr_fun and
 > std::pointer_to_unary_function templates, whose argument (and ctor)
 > are explicitly pointers to function (with C++ linkage).
 
 I think what I was trying to say (but didn't do a very good job)
 was that in the call to std::transform (..., toupper), the compiler
 can't choose between the two overloads of the function: extern "C"
 toupper (int) and the two-argument template toupper, and it cannot
 even deduce the type of the template toupper. If only the extern "C"
 function were found, the call would be unambiguous. The linkage was
 a red herring (gcc doesn't distinguish between one and the other
 but it doesn't have anything to do with the the error). Sorry if
 I confused things.
 
 > 
 > I cannot see anything that keeps one from using the toupper/tolower
 > from <cctype> with transform, and the fact that gcc won't allow it
 > should be considered a bug.
 
 Yes, but only if it's the only available function. The other comes
 from <locale> which is probably indirectly #included by <iostream>.
 
 Regards
 Martin