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| author | Jonathan Wakely <jwakely@redhat.com> | 2022-06-23 18:17:30 +0100 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2022-06-27 11:08:16 +0100 |
| commit | 48099f7dafe8d10e92ddfc88c0fd5bfbb435d3d6 (patch) | |
| tree | 97cd15f174865a1c8e5d2bc863b78797181f4307 | |
| parent | 153689603fd6aeb95b20a86f3a04fc5b93b01b09 (diff) | |
| download | gcc-48099f7dafe8d10e92ddfc88c0fd5bfbb435d3d6.zip gcc-48099f7dafe8d10e92ddfc88c0fd5bfbb435d3d6.tar.gz gcc-48099f7dafe8d10e92ddfc88c0fd5bfbb435d3d6.tar.bz2 | |
libstdc++: Invert relationship between std::is_clock and std::is_clock_v
This redefines std::is_clock in terms of std::is_clock_v, instead of the
other way around. This avoids instantiatng the class template for code
that only uses the variable template.
libstdc++-v3/ChangeLog:
* include/bits/chrono.h (is_clock_v): Define to false.
(is_clock_v<T>): Define partial specialization for true cases.
(is_clock): Define in terms of is_clock_v.
| -rw-r--r-- | libstdc++-v3/include/bits/chrono.h | 45 |
1 files changed, 18 insertions, 27 deletions
diff --git a/libstdc++-v3/include/bits/chrono.h b/libstdc++-v3/include/bits/chrono.h index 745f9a8..05987ca 100644 --- a/libstdc++-v3/include/bits/chrono.h +++ b/libstdc++-v3/include/bits/chrono.h @@ -273,16 +273,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION #endif // C++17 #if __cplusplus > 201703L - template<typename _Tp> - struct is_clock; - - template<typename _Tp> - inline constexpr bool is_clock_v = is_clock<_Tp>::value; - #if __cpp_lib_concepts template<typename _Tp> - struct is_clock : false_type - { }; + inline constexpr bool is_clock_v = false; template<typename _Tp> requires requires { @@ -298,32 +291,30 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION requires same_as<typename _Tp::time_point::duration, typename _Tp::duration>; } - struct is_clock<_Tp> : true_type - { }; + inline constexpr bool is_clock_v<_Tp> = true; #else template<typename _Tp, typename = void> - struct __is_clock_impl : false_type - { }; + inline constexpr bool is_clock_v = false; template<typename _Tp> - struct __is_clock_impl<_Tp, - void_t<typename _Tp::rep, typename _Tp::period, - typename _Tp::duration, - typename _Tp::time_point::duration, - decltype(_Tp::is_steady), - decltype(_Tp::now())>> - : __and_<is_same<typename _Tp::duration, - duration<typename _Tp::rep, typename _Tp::period>>, - is_same<typename _Tp::time_point::duration, - typename _Tp::duration>, - is_same<decltype(&_Tp::is_steady), const bool*>, - is_same<decltype(_Tp::now()), typename _Tp::time_point>>::type - { }; + inline constexpr bool + is_clock_v<_Tp, void_t<typename _Tp::rep, typename _Tp::period, + typename _Tp::duration, + typename _Tp::time_point::duration, + decltype(_Tp::is_steady), + decltype(_Tp::now())>> + = __and_v<is_same<typename _Tp::duration, + duration<typename _Tp::rep, typename _Tp::period>>, + is_same<typename _Tp::time_point::duration, + typename _Tp::duration>, + is_same<decltype(&_Tp::is_steady), const bool*>, + is_same<decltype(_Tp::now()), typename _Tp::time_point>>; +#endif template<typename _Tp> - struct is_clock : __is_clock_impl<_Tp>::type + struct is_clock + : bool_constant<is_clock_v<_Tp>> { }; -#endif #endif // C++20 #if __cplusplus >= 201703L |