Re: [PATCH] don't store temporary value returned from c_str()

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+Date: Sat, 27 Apr 2013 17:59:22 +0200\r
+From: Vladimir Marek <Vladimir.Marek@Oracle.COM>\r
+To: notmuch@notmuchmail.org\r
+Subject: Re: [PATCH] don't store temporary value returned from c_str()\r
+Message-ID: <20130427155922.GA17459@vi64-x3-2e-prg06.cz.oracle.com>\r
+References: <1366405933-17223-1-git-send-email-Vladimir.Marek@oracle.com>\r
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+\r
+> > const char*\r
+> > string::c_str(void) {\r
+> >    char buf[100];\r
+> >\r
+> >    strcpy (buf, this->internal_representation);\r
+> >    return buf;\r
+> > }\r
+> \r
+> Isn't that undefined behavior, returning a pointer to a (non-static)\r
+> local variable?\r
+\r
+Right, I was trying to bring up an example and this one is not very\r
+good. Maybe something like that:\r
+\r
+\r
+const char*\r
+c_str() {\r
+       vector<char> X(my_string);\r
+       return &X[0];\r
+};\r
+\r
+char buf[];\r
+strcpy(buf, c_str());\r
+\r
+X destructor is called after strcpy is done.\r
+\r
+char buf[];\r
+char *tmp=c_str();\r
+strcpy(buf, tmp);\r
+\r
+X destructor is called before strcpy.\r
+\r
+At least this is how I understand it.\r
+\r
+-- \r
+       Vlad\r