From b8b5398cbdf99f6c977a6a1749628538ba436a0b Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Tue, 14 Aug 2018 14:55:21 +0100 Subject: [PATCH] Simplify overflow checks in duration literals * include/std/chrono (__check_overflow): Simplify definition. (_Checked_integral_constant): Remove. From-SVN: r263537 --- libstdc++-v3/ChangeLog | 3 +++ libstdc++-v3/include/std/chrono | 18 ++++-------------- 2 files changed, 7 insertions(+), 14 deletions(-) diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 15ff3db6134..cf69f216072 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,8 @@ 2018-08-14 Jonathan Wakely + * include/std/chrono (__check_overflow): Simplify definition. + (_Checked_integral_constant): Remove. + PR libstdc++/86846 * src/c++17/default_resource.h: New file, defining default_res. * src/c++17/memory_resource.cc [ATOMIC_POINTER_LOCK_FREE != 2] diff --git a/libstdc++-v3/include/std/chrono b/libstdc++-v3/include/std/chrono index da03fdccce4..871c896144a 100644 --- a/libstdc++-v3/include/std/chrono +++ b/libstdc++-v3/include/std/chrono @@ -900,24 +900,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION { #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wliteral-suffix" - template - struct _Checked_integral_constant - : integral_constant<_Rep, static_cast<_Rep>(_Val)> - { - static_assert(_Checked_integral_constant::value >= 0 - && _Checked_integral_constant::value == _Val, - "literal value cannot be represented by duration type"); - }; - template constexpr _Dur __check_overflow() { using _Val = __parse_int::_Parse_int<_Digits...>; - using _Rep = typename _Dur::rep; - // TODO: should be simply integral_constant<_Rep, _Val::value> - // but GCC doesn't reject narrowing conversions to _Rep. - using _CheckedVal = _Checked_integral_constant<_Rep, _Val::value>; - return _Dur{_CheckedVal::value}; + constexpr typename _Dur::rep __repval = _Val::value; + static_assert(__repval >= 0 && __repval == _Val::value, + "literal value cannot be represented by duration type"); + return _Dur(__repval); } constexpr chrono::duration> -- 2.30.2