On Tue, Aug 14, 2018 at 02:55:17PM +0100, Jonathan Wakely wrote:
> * include/std/chrono (__check_overflow): Simplify definition.
> (_Checked_integral_constant): Remove.
>
> Tested x86_64-linux, committed to trunk.
>
>
> commit c0dec9d05de4695136694f78f2f76e3c9f15b3f1
> Author: Jonathan Wakely <jwak...@redhat.com>
> Date: Tue Aug 14 14:33:38 2018 +0100
>
> Simplify overflow checks in duration literals
>
> * include/std/chrono (__check_overflow): Simplify definition.
> (_Checked_integral_constant): Remove.
>
> 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<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.
Note that I fixed 57891 yesterday. Or is this either 65043 or 78244?
> - 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>>
Marek
