Re: _GLIBCXX_USE_C99 not working?

[Václav Haisman <v dot haisman at sh dot cvut dot cz>]

Christian Franke wrote:
> Defining _GLIBCXX_USE_C99 does not work with current Cygwin C++ includes.
> 
> Testcase:
> 
> #define _GLIBCXX_USE_C99 1 // need std::llabs()
> 
> #include <cstdlib>
> 
> long long f(long long x)
> {
>    return std::llabs(x);
> }
> 
> 
> Compile fails with:
> 
> /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/cstdlib:181:
>  error: `::strtold' has not been declared
> /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/cstdlib:200:
>  error: `__gnu_cxx::strtold' has not been declared
> 
> 
> The function strtold() does actually not exist in stdlib.h
> and the corresponding _GLIBCXX_HAVE_STRTOLD in
> /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/i686-pc-cygwin/bits/c++config.h
> 
> is not set.
> 
> But "using ::strtold" exists in the "#if _GLIBCXX_USE_C99" part of
> /usr/lib/gcc/i686-pc-cygwin/3.4.4/include/c++/cstdlib
> 
> Workaround: delete the two "using ::strtold" lines from cstdlib.
> 
> Christian
Look into the cstdlib header. You will find that llabs(long long) and
abs(long long) are in the __gnu_cxx namespace there. It is because long
long is not C++ standard type.

--
Vaclav Haisman

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