// Given the following C++ code void f( char * str) { char * & m = const_cast<char *>( str); } /* then g++ 332 says not a lot. [dcb@localhost src]$ ~/gnu/gcc332/results/bin/g++ -c -g -O2 -Wall -ansi -pedantic cc.cc cc.cc: In function `void f(char*)': cc.cc:7: warning: unused variable `char*&m' [dcb@localhost src]$ But Intel C++ 8.0 says [dcb@localhost src]$ icc cc.cc cc.cc(7): error: initial value of reference to non-const must be an lvalue char * & m = const_cast<char *>( str); ^ compilation aborted for cc.cc (code 2) [dcb@localhost src]$ One compiler must be wrong. */
5.2.11/1 clearly states that the result of a const_cast<T> is of type T. In your case, it is a char*, so it is not an lvalue. Thus, gcc must be wrong. Note also 5.2.11/4. W.
Agreed, GCC is wrong here.
Retargeting to 3.4.1, being a regression on that release branch.
Working on a fix.
Subject: Bug 14211 CVSROOT: /cvs/gcc Module name: gcc Changes by: mmitchel@gcc.gnu.org 2004-06-10 14:26:23 Modified files: gcc/cp : ChangeLog parser.c pt.c typeck.c Added files: gcc/testsuite/g++.dg/conversion: const1.C reinterpret1.C gcc/testsuite/g++.dg/template: enum2.C error13.C Log message: PR c++/15227 * parser.c (cp_parser_direct_declarator): Robustify. PR c++/15877 * pt.c (tsubst_copy): Use decl_constant_value on enumeration constants in non-dependent contexts. PR c++/14211 PR c++/15076 * typeck.c (build_static_cast): Wrap casts in NON_LVALUE_EXPR when necessary. PR c++/14211 * g++.dg/conversion/const1.C: New test. PR c++/15076 * g++.dg/conversion/reinterpret1.C: New test. PR c++/15877 * g++.dg/template/enum2.C: New test. PR c++/15227 * g++.dg/template/error13.C: New test. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.4089&r2=1.4090 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/parser.c.diff?cvsroot=gcc&r1=1.202&r2=1.203 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/pt.c.diff?cvsroot=gcc&r1=1.860&r2=1.861 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/typeck.c.diff?cvsroot=gcc&r1=1.548&r2=1.549 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/conversion/const1.C.diff?cvsroot=gcc&r1=NONE&r2=1.1 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/conversion/reinterpret1.C.diff?cvsroot=gcc&r1=NONE&r2=1.1 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/enum2.C.diff?cvsroot=gcc&r1=NONE&r2=1.1 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/error13.C.diff?cvsroot=gcc&r1=NONE&r2=1.1
Subject: Bug 14211 CVSROOT: /cvs/gcc Module name: gcc Branch: gcc-3_4-branch Changes by: mmitchel@gcc.gnu.org 2004-06-10 14:26:50 Modified files: gcc/cp : ChangeLog parser.c pt.c typeck.c Added files: gcc/testsuite/g++.dg/conversion: const1.C reinterpret1.C gcc/testsuite/g++.dg/template: enum2.C error13.C Log message: PR c++/15227 * parser.c (cp_parser_direct_declarator): Robustify. PR c++/15877 * pt.c (tsubst_copy): Use decl_constant_value on enumeration constants in non-dependent contexts. PR c++/14211 PR c++/15076 * typeck.c (build_static_cast): Wrap casts in NON_LVALUE_EXPR when necessary. PR c++/14211 * g++.dg/conversion/const1.C: New test. PR c++/15076 * g++.dg/conversion/reinterpret1.C: New test. PR c++/15877 * g++.dg/template/enum2.C: New test. PR c++/15227 * g++.dg/template/error13.C: New test. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.3892.2.119&r2=1.3892.2.120 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/parser.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.157.2.32&r2=1.157.2.33 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/pt.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.816.2.29&r2=1.816.2.30 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/typeck.c.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=1.519.2.19&r2=1.519.2.20 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/conversion/const1.C.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=NONE&r2=1.1.2.1 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/conversion/reinterpret1.C.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=NONE&r2=1.1.2.1 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/enum2.C.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=NONE&r2=1.1.2.1 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/error13.C.diff?cvsroot=gcc&only_with_tag=gcc-3_4-branch&r1=NONE&r2=1.1.2.1
Fixed in GCC 3.4.1.
*** Bug 15076 has been marked as a duplicate of this bug. ***