2010-07-11  Paolo Carlini  <paolo.carlini@oracle.com>

	* include/std/type_traits (is_convertible): Use SFINAE.
	* testsuite/20_util/make_signed/requirements/typedefs_neg.cc: Adjust
	dg-error line numbers.
	* testsuite/20_util/make_unsigned/requirements/typedefs_neg.cc:
	Likewise.
	* testsuite/20_util/declval/requirements/1_neg.cc: Likewise.

From-SVN: r162056