type_traits (common_type): Implement LWG 2141.
2012-10-24 Daniel Krugler <daniel.kruegler@gmail.com>
* include/std/type_traits (common_type): Implement LWG 2141.
* testsuite/20_util/duration/requirements/sfinae_friendly_1.cc:
Update.
* testsuite/20_util/common_type/requirements/typedefs-1.cc: Likewise.
* testsuite/20_util/common_type/requirements/sfinae_friendly_1.cc:
Likewise.
* testsuite/20_util/common_type/requirements/sfinae_friendly_2.cc:
Likewise.
* testsuite/20_util/common_type/requirements/typedefs-2.cc: Likewise.
From-SVN: r192780