[PATCH] Add noexcept to std::integral_constant members

[Jonathan Wakely]

C++14 added noexcept to the integral_constant member functions, and it
should always have been on the integer_sequence one.

        * include/std/type_traits (integral_constant): Make member functions
        noexcept (LWG 2346).
        * include/std/utility (integer_sequence): Likewise.

Tested powerpc64le-linux, committed to trunk.



commit 63ab060f8e958744dd06f09d7c639f45e66d09c0
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Fri Dec 1 13:52:08 2017 +0000

    Add noexcept to std::integral_constant members
    
            * include/std/type_traits (integral_constant): Make member functions
            noexcept (LWG 2346).
            * include/std/utility (integer_sequence): Likewise.

diff --git a/libstdc++-v3/include/std/type_traits 
b/libstdc++-v3/include/std/type_traits
index 723c137f5b9..1d639e452f3 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -71,12 +71,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       static constexpr _Tp                  value = __v;
       typedef _Tp                           value_type;
       typedef integral_constant<_Tp, __v>   type;
-      constexpr operator value_type() const { return value; }
+      constexpr operator value_type() const noexcept { return value; }
 #if __cplusplus > 201103L
 
 #define __cpp_lib_integral_constant_callable 201304
 
-      constexpr value_type operator()() const { return value; }
+      constexpr value_type operator()() const noexcept { return value; }
 #endif
     };
 
diff --git a/libstdc++-v3/include/std/utility b/libstdc++-v3/include/std/utility
index e7386320e2a..da17928feee 100644
--- a/libstdc++-v3/include/std/utility
+++ b/libstdc++-v3/include/std/utility
@@ -321,7 +321,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     struct integer_sequence
     {
       typedef _Tp value_type;
-      static constexpr size_t size() { return sizeof...(_Idx); }
+      static constexpr size_t size() noexcept { return sizeof...(_Idx); }
     };
 
   /// Alias template make_integer_sequence