Cleanup one more <forward_list> test

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@300417 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/containers/sequences/forwardlist/forwardlist.cons/size.fail.cpp

@@ -1,35 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-// <forward_list>
-
-// explicit forward_list(size_type n);
-
-#include <forward_list>
-#include <cassert>
-
-#include "DefaultOnly.h"
-
-int main()
-{
-    {
-        typedef DefaultOnly T;
-        typedef std::forward_list<T> C;
-        unsigned N = 10;
-        C c = N;
-        unsigned n = 0;
-        for (C::const_iterator i = c.begin(), e = c.end(); i != e; ++i, ++n)
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-            assert(*i == T());
-#else
-            ;
-#endif
-        assert(n == N);
-    }
-}

test/std/containers/sequences/forwardlist/forwardlist.cons/size.pass.cpp

@@ -36,6 +36,11 @@ void check_allocator(unsigned n, Allocator const &alloc = Allocator())
 
 int main()
 {
+    { // test that the ctor is explicit
+      typedef std::forward_list<DefaultOnly> C;
+      static_assert((std::is_constructible<C, size_t>::value), "");
+      static_assert((!std::is_convertible<size_t, C>::value), "");
+    }
     {
         typedef DefaultOnly T;
         typedef std::forward_list<T> C;