Similar to the previous commit that made is_integral_v<__int128>
unconditionally true, this makes is_floating_point_v<__float128>
unconditionally true. With the new extended floating-point types in
C++23 (std::float64_t etc.) it seems unhelpful for is_floating_point_v
to be true for them, but not for __float128. Especially as it is true on
some targets, because __float128 is just a typedef for long double.
This change makes is_floating_point_v<__float128> true whenever the type
is defined, giving less surprising and more portable behaviour.
libstdc++-v3/ChangeLog:
* include/bits/cpp_type_traits.h (__is_floating<__float128>):
Do not depend on __STRICT_ANSI__.
* include/bits/stl_algobase.h (__size_to_integer(__float128)):
Likewise.
* include/std/type_traits (__is_floating_point_helper<__float128>):
Likewise.
---
Tested x86_64-linux and powerpc64le-linux.
I don't _think_ this affects how <format> handles __float128, because
there are std::formatter specializations for each floating-point type,
rather than a partial specialization that uses std::floating_point.
libstdc++-v3/include/bits/cpp_type_traits.h | 9 +++++++++
libstdc++-v3/include/bits/stl_algobase.h | 2 +-
libstdc++-v3/include/std/type_traits | 2 +-
3 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/include/bits/cpp_type_traits.h
b/libstdc++-v3/include/bits/cpp_type_traits.h
index 770ad94b3b4d..38cea4c67b76 100644
--- a/libstdc++-v3/include/bits/cpp_type_traits.h
+++ b/libstdc++-v3/include/bits/cpp_type_traits.h
@@ -313,6 +313,15 @@ __INT_N(__int128)
typedef __true_type __type;
};
+#ifdef _GLIBCXX_USE_FLOAT128
+ template<>
+ struct __is_floating<__float128>
+ {
+ enum { __value = 1 };
+ typedef __true_type __type;
+ };
+#endif
+
#ifdef __STDCPP_FLOAT16_T__
template<>
struct __is_floating<_Float16>
diff --git a/libstdc++-v3/include/bits/stl_algobase.h
b/libstdc++-v3/include/bits/stl_algobase.h
index 71ef2335a311..b104ec2536a0 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -1065,7 +1065,7 @@ _GLIBCXX_END_NAMESPACE_CONTAINER
__size_to_integer(double __n) { return (long long)__n; }
inline _GLIBCXX_CONSTEXPR long long
__size_to_integer(long double __n) { return (long long)__n; }
-#if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
+#ifdef _GLIBCXX_USE_FLOAT128
__extension__ inline _GLIBCXX_CONSTEXPR long long
__size_to_integer(__float128 __n) { return (long long)__n; }
#endif
diff --git a/libstdc++-v3/include/std/type_traits
b/libstdc++-v3/include/std/type_traits
index e88d04e44d76..78a5ee8c0eb4 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -532,7 +532,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
: public true_type { };
#endif
-#if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
+#ifdef _GLIBCXX_USE_FLOAT128
template<>
struct __is_floating_point_helper<__float128>
: public true_type { };
--
2.50.0
