re PR libstdc++/12657 (Resolution of DR 292 (WP) still unimplemented)

2003-10-22  Paolo Carlini  <pcarlini@suse.de>

	PR libstdc++/12657
	* include/bits/basic_ios.tcc (copyfmt(const basic_ios&)):
	Implement resolution of DR 292 (WP).
	* docs/html/ext/howto.html: Add entry for DR 292.

From-SVN: r72803

libstdc++-v3/ChangeLog

+2003-10-22  Paolo Carlini  <pcarlini@suse.de>
+
+	PR libstdc++/12657
+	* include/bits/basic_ios.tcc (copyfmt(const basic_ios&)):
+	Implement resolution of DR 292 (WP).
+	* docs/html/ext/howto.html: Add entry for DR 292.
+
 2003-10-21  Benjamin Kosnik  <bkoz@redhat.com>
 
 	* include/ext/mt_allocator.h: Change include to gthr.h.

libstdc++-v3/docs/html/ext/howto.html

@@ -640,6 +640,12 @@
     <dd>Similar to 118.
     </dd>
 
+    <dt><a href="lwg-defects.html#292">292</a>:
+        <em>Effects of a.copyfmt (a)</em>
+    </dt>
+    <dd>If <code>(this == &amp;rhs)</code> do nothing.
+    </dd>
+
 <!--
     <dt><a href="lwg-defects.html#"></a>:
         <em></em>

libstdc++-v3/include/bits/basic_ios.tcc

@@ -60,6 +60,11 @@ namespace std
     basic_ios<_CharT, _Traits>&
     basic_ios<_CharT, _Traits>::copyfmt(const basic_ios& __rhs)
     {
+      // _GLIBCXX_RESOLVE_LIB_DEFECTS
+      // 292. effects of a.copyfmt (a)
+      if (this == &__rhs)
+	return *this;
+
       // Per 27.1.1, do not call imbue, yet must trash all caches
       // associated with imbue()