Here's a small tweak to __numeric_traits that I decided to do after
the previous patch.
Tested on powerpc64le-linux. Committed to trunk.
commit d21776ef90361e66401cd99c8ff0d98b46d3b0d6
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Thu Nov 12 13:31:02 2020
libstdc++: Simplify __numeric_traits definition
This changes the __numeric_traits primary template to assume its
argument is an integer type. For the three floating point types that are
supported by __numeric_traits_floating an explicit specialization of
__numeric_traits chooses the right base class.
This improves the failure mode for using __numeric_traits with an
unsupported type. Previously it would use __numeric_traits_floating as
the base class, and give somewhat obscure errors for trying to access
the static data members. Now it will use __numeric_traits_integer which
has a static_assert to check for supported types.
As a side effect of this change there is no need to instantiate
__conditional_type to decide which base class to use.
libstdc++-v3/ChangeLog:
* include/ext/numeric_traits.h (__numeric_traits): Change
primary template to always derive from __numeric_traits_integer.
(__numeric_traits<float>, __numeric_traits<double>)
(__numeric_traits<long double>): Add explicit specializations.
diff --git a/libstdc++-v3/include/ext/numeric_traits.h b/libstdc++-v3/include/ext/numeric_traits.h
index c29f9f21d1aa..2cac7f1d1edc 100644
--- a/libstdc++-v3/include/ext/numeric_traits.h
+++ b/libstdc++-v3/include/ext/numeric_traits.h
@@ -176,19 +176,32 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Value>
const int __numeric_traits_floating<_Value>::__max_exponent10;
- template<typename _Value>
- struct __numeric_traits
- : public __conditional_type<__is_integer_nonstrict<_Value>::__value,
- __numeric_traits_integer<_Value>,
- __numeric_traits_floating<_Value> >::__type
- { };
-
-_GLIBCXX_END_NAMESPACE_VERSION
-} // namespace
-
#undef __glibcxx_floating
#undef __glibcxx_max_digits10
#undef __glibcxx_digits10
#undef __glibcxx_max_exponent10
+ template<typename _Value>
+ struct __numeric_traits
+ : public __numeric_traits_integer<_Value>
+ { };
+
+ template<>
+ struct __numeric_traits<float>
+ : public __numeric_traits_floating<float>
+ { };
+
+ template<>
+ struct __numeric_traits<double>
+ : public __numeric_traits_floating<double>
+ { };
+
+ template<>
+ struct __numeric_traits<long double>
+ : public __numeric_traits_floating<long double>
+ { };
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+
#endif
