[patch] LWG 2440 std::seed_seq::size() should be noexcept

[Jonathan Wakely]

http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2015/n4383.html#2440

This was resolved as a defect and voted into the working paper in
Lenexa. As an extension we can also make the default constructor
noexcept.

Tested powerpc64le-linux, committed to trunk.

commit 1629bfd40e615b5130d72d9759ca82cfca8f74d2
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Wed May 13 13:13:37 2015 +0100

    	* include/bits/random.h (seed_seq): More noexcept (LWG 2440).

diff --git a/libstdc++-v3/include/bits/random.h b/libstdc++-v3/include/bits/random.h
index 501243d..5905e60 100644
--- a/libstdc++-v3/include/bits/random.h
+++ b/libstdc++-v3/include/bits/random.h
@@ -6023,13 +6023,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    */
   class seed_seq
   {
-
   public:
     /** The type of the seed vales. */
     typedef uint_least32_t result_type;
 
     /** Default constructor. */
-    seed_seq()
+    seed_seq() noexcept
     : _M_v()
     { }
 
@@ -6045,7 +6044,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       generate(_RandomAccessIterator __begin, _RandomAccessIterator __end);
 
     // property functions
-    size_t size() const
+    size_t size() const noexcept
     { return _M_v.size(); }
 
     template<typename OutputIterator>
@@ -6058,7 +6057,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     seed_seq& operator=(const seed_seq&) = delete;
 
   private:
-    ///
     std::vector<result_type> _M_v;
   };