shared_ptr.h (shared_ptr::shared_ptr(nullptr_t)): Use delegating constructor.

	* include/bits/shared_ptr.h (shared_ptr::shared_ptr(nullptr_t)): Use
	delegating constructor.
	* include/bits/shared_ptr_base.h
	(__shared_ptr::__shared_ptr(nullptr_t)): Likewise

From-SVN: r209428

libstdc++-v3/ChangeLog

@@ -15,6 +15,11 @@
 	* include/bits/atomic_base.h (__atomic_base<_PTp*>::_M_type_size): Add
 	const to constexpr member functions.
 
+	* include/bits/shared_ptr.h (shared_ptr::shared_ptr(nullptr_t)): Use
+	delegating constructor.
+	* include/bits/shared_ptr_base.h
+	(__shared_ptr::__shared_ptr(nullptr_t)): Likewise
+
 2014-04-14  Jonathan Wakely  <jwakely@redhat.com>
 
 	* include/bits/stl_vector.h (_Vector_base::_Vector_impl,

libstdc++-v3/include/bits/shared_ptr.h

@@ -262,8 +262,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        *  @param  __p  A null pointer constant.
        *  @post   use_count() == 0 && get() == nullptr
        */
-      constexpr shared_ptr(nullptr_t __p) noexcept
-      : __shared_ptr<_Tp>(__p) { }
+      constexpr shared_ptr(nullptr_t __p) noexcept : shared_ptr() { }
 
       shared_ptr& operator=(const shared_ptr&) noexcept = default;
 

libstdc++-v3/include/bits/shared_ptr_base.h

@@ -963,10 +963,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	__shared_ptr(std::auto_ptr<_Tp1>&& __r);
 #endif
 
-      /* TODO: use delegating constructor */
-      constexpr __shared_ptr(nullptr_t) noexcept
-      : _M_ptr(0), _M_refcount()
-      { }
+      constexpr __shared_ptr(nullptr_t) noexcept : __shared_ptr() { }
 
       template<typename _Tp1>
 	__shared_ptr&