2011-05-09 Paolo Carlini <paolo.carlini@oracle.com>

2011-05-09  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/48933
	* include/c_global/cmath (acosh, asinh, atanh, cbrt, copysign,
	erf, erfc, exp2, expm1, fdim, fma, fmax, hypot, ilogb, lgamma,
	llrint, llround, log1p, log2, logb, lrint, lround, nearbyint,
	nextafter, nexttoward, remainder, remquo, rint, round, scalbln,
	scalbn, tgamma, trunc): Use __enable_if on the return type.
	* include/tr1/cmath: Likewise.
	* testsuite/26_numerics/headers/cmath/overloads_c++0x_neg.cc: New.
	* testsuite/tr1/8_c_compatibility/cmath/overloads_neg.cc: Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@173574 138bc75d-0d04-0410-961f-82ee72b054a4