[Bug libstdc++/54451] c++11/random.cc build failure when _GLIBCXX_USE_C99_STDINT_TR1 is not defined in config.h

[rbmj at verizon dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54451

--- Comment #6 from rbmj at verizon dot net 2012-09-09 18:08:11 UTC ---
Making local changes to bring stdint.h into compliance works for me as well.

(In reply to comment #5)
> (In reply to comment #4)
> > Maybe it would be nice to use #error in header file to inform the user that
> > this feature is not supported for target system (nicer than to get linker error
> > later)
> 
> You won't get a linker error, if the macro is not defined then the types in
> <random> are not declared, so code using them won't compile.

However, you will get weird "std::random_device" not declared errors, which
will seem strange to any end user.

> Using #error would prevent #include <random> which I don't think is a good
> idea. There's no harm including the header as long as you don't try to use
> types which require a working <stdint.h>

Agreed.  But could we use #warning to tell the user what's happening (if
portability is an issue we can check for __GNUC__) without going through the
source?

> The fix is to simply make random.cc check the macro. This is what we already do
> in future.cc and thread.cc and mutex.cc and other files too.

Also true.