libstdc++: Simplify n-ary arithmetic promotion traits

The std::complex partial specializations have been unnecessary since
774c3d8647cc7012937cfc9d2d6dacc85b6cf8e9

Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:

	* include/ext/type_traits.h (__promote_2, __promote_3)
	(__promote_4): Redfine as alias templates using __promoted_t.
	* include/std/complex (__promote_2): Remove partial
	specializations for std::complex.

diff --git a/libstdc++-v3/include/ext/type_traits.h b/libstdc++-v3/include/ext/type_traits.h
index 065edb4..fed78d3 100644 (file)
--- a/libstdc++-v3/include/ext/type_traits.h
+++ b/libstdc++-v3/include/ext/type_traits.h
@@ -189,9 +189,22 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     { typedef float __type; };
 
 #if __cpp_fold_expressions
+
   template<typename... _Tp>
     using __promoted_t = decltype((typename __promote<_Tp>::__type(0) + ...));
-#endif
+
+  // Deducing the promoted type is done by __promoted_t<_Tp...>,
+  // then __promote is used to provide the nested __type member.
+  template<typename _Tp, typename _Up>
+    using __promote_2 = __promote<__promoted_t<_Tp, _Up>>;
+
+  template<typename _Tp, typename _Up, typename _Vp>
+    using __promote_3 = __promote<__promoted_t<_Tp, _Up, _Vp>>;
+
+  template<typename _Tp, typename _Up, typename _Vp, typename _Wp>
+    using __promote_4 = __promote<__promoted_t<_Tp, _Up, _Vp, _Wp>>;
+
+#else
 
   template<typename _Tp, typename _Up,
            typename _Tp2 = typename __promote<_Tp>::__type,
@@ -219,6 +232,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     {
       typedef __typeof__(_Tp2() + _Up2() + _Vp2() + _Wp2()) __type;
     };
+#endif
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace

diff --git a/libstdc++-v3/include/std/complex b/libstdc++-v3/include/std/complex
index c2f6421..a5b4406 100644 (file)
--- a/libstdc++-v3/include/std/complex
+++ b/libstdc++-v3/include/std/complex
@@ -1557,35 +1557,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
 
-namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
-{
-_GLIBCXX_BEGIN_NAMESPACE_VERSION
-
-  // See ext/type_traits.h for the primary template.
-  template<typename _Tp, typename _Up>
-    struct __promote_2<std::complex<_Tp>, _Up>
-    {
-    public:
-      typedef std::complex<typename __promote_2<_Tp, _Up>::__type> __type;
-    };
-
-  template<typename _Tp, typename _Up>
-    struct __promote_2<_Tp, std::complex<_Up> >
-    {
-    public:
-      typedef std::complex<typename __promote_2<_Tp, _Up>::__type> __type;
-    };
-
-  template<typename _Tp, typename _Up>
-    struct __promote_2<std::complex<_Tp>, std::complex<_Up> >
-    {
-    public:
-      typedef std::complex<typename __promote_2<_Tp, _Up>::__type> __type;
-    };
-
-_GLIBCXX_END_NAMESPACE_VERSION
-} // namespace
-
 #if __cplusplus >= 201103L
 
 namespace std _GLIBCXX_VISIBILITY(default)