Merged value_init fixes (extra tests + documentation) from trunk, see #3472, #3869.

[SVN r63638]

initialized_test_fail1.cpp

@@ -0,0 +1,33 @@
+// Copyright 2010, Niels Dekker.
+//
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+//
+// Test program for boost::initialized<T>. Must fail to compile.
+//
+// Initial: 2 May 2010
+
+#include <boost/utility/value_init.hpp>
+
+namespace
+{
+  void direct_initialize_from_int()
+  {
+    // Okay: initialized<T> supports direct-initialization from T.
+    boost::initialized<int> direct_initialized_int(1);
+  }
+
+  void copy_initialize_from_int()
+  {
+    // The following line should not compile, because initialized<T> 
+    // was not intended to supports copy-initialization from T.
+    boost::initialized<int> copy_initialized_int = 1;
+  }
+}
+
+int main()
+{
+  // This should fail to compile, so there is no need to call any function.
+  return 0;
+}