id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
6156	fenv.hpp broken on clang+glibc	Marc Glisse <marc.glisse@…>	John Maddock	"Hello,

with clang and glibc, boost doesn't protect against multiple inclusion of bits/fenv.h:

#include <fenv.h>
#include <boost/lexical_cast.hpp>

/localhome/glisse2/include/boost/detail/fenv.hpp:22:11: warning: '_FENV_H' macro redefined
/usr/include/fenv.h:24:9: note: previous definition is here
/usr/include/x86_64-linux-gnu/bits/fenv.h:30:5: error: redefinition of enumerator 'FE_INVALID'
...

Someone apparently thought it was a good idea to add some subtleties to fenv.hpp to help people who misconfigured clang, but that is imho a bad idea and the special case should be removed (note that clang-3.0 has a good default configuration). If you insist on keeping it, please ensure that _FENV_H is not defined."	Bugs	closed	To Be Determined	math	Boost 1.48.0	Problem	fixed		antoshkka@…