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Simplify overflow checks in duration literals

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* include/std/chrono (__check_overflow): Simplify definition.
	(_Checked_integral_constant): Remove.

From-SVN: r263537
This commit is contained in:
Jonathan Wakely 2018-08-14 14:55:21 +01:00 • committed by Jonathan Wakely
parent 26e130482e
commit b8b5398cbd
2 changed files with 7 additions and 14 deletions
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3
libstdc++-v3/ChangeLog
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@ -1,5 +1,8 @@
2018-08-14 Jonathan Wakely <jwakely@redhat.com>
* 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]

18
libstdc++-v3/include/std/chrono
View file

@ -900,24 +900,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
{
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wliteral-suffix"
template<typename _Rep, unsigned long long _Val>
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<typename _Dur, char... _Digits>
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<long double, ratio<3600,1>>