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* [Bug c++/50835] New: [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template @ 2011-10-23 2:10 mimomorin at gmail dot com 2011-10-23 11:47 ` [Bug c++/50835] " daniel.kruegler at googlemail dot com ` (6 more replies) 0 siblings, 7 replies; 8+ messages in thread From: mimomorin at gmail dot com @ 2011-10-23 2:10 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50835 Bug #: 50835 Summary: [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template Classification: Unclassified Product: gcc Version: 4.7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned@gcc.gnu.org ReportedBy: mimomorin@gmail.com Created attachment 25578 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25578 Test case (which incorrectly fails to be compiled on gcc-4.7) Suppose we have the following class template<typename T> struct rvalue_probe { explicit rvalue_probe(T &t) : value(t) {} operator T () { return value; } operator T&() const { return value; } T& value; }; Then, // std::vector<int> v; true ? rvalue_probe<std::vector<int> >(v) : v should be evaluated to an lvalue. But in a function template, this is incorrectly evaluated to an rvalue. Tested on gcc-4.7.0 20111022 (in a C++03 mode). ^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/50835] [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template 2011-10-23 2:10 [Bug c++/50835] New: [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template mimomorin at gmail dot com @ 2011-10-23 11:47 ` daniel.kruegler at googlemail dot com 2011-10-23 11:50 ` daniel.kruegler at googlemail dot com ` (5 subsequent siblings) 6 siblings, 0 replies; 8+ messages in thread From: daniel.kruegler at googlemail dot com @ 2011-10-23 11:47 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50835 --- Comment #1 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2011-10-23 11:47:19 UTC --- Simplified test case: //--- template<typename> struct vector {}; template<typename T> struct rvalue_probe { explicit rvalue_probe(T &t) : value(t) {} operator T&() const { return value; } T& value; }; template <typename T> void should_be_lvalue(T&) { } template <typename> void f() { vector<int> v; should_be_lvalue(true ? rvalue_probe<vector<int> >(v) : v); // Error } //--- The problem exists in C++0x mode as well. ^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/50835] [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template 2011-10-23 2:10 [Bug c++/50835] New: [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template mimomorin at gmail dot com 2011-10-23 11:47 ` [Bug c++/50835] " daniel.kruegler at googlemail dot com @ 2011-10-23 11:50 ` daniel.kruegler at googlemail dot com 2011-10-23 12:24 ` daniel.kruegler at googlemail dot com ` (4 subsequent siblings) 6 siblings, 0 replies; 8+ messages in thread From: daniel.kruegler at googlemail dot com @ 2011-10-23 11:50 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50835 --- Comment #2 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2011-10-23 11:50:17 UTC --- Further simplification: //--- struct vector {}; template<typename T> struct rvalue_probe { explicit rvalue_probe(T &t) : value(t) {} operator T&() const { return value; } T& value; }; template <typename T> void should_be_lvalue(T&) { } template <typename> void f() { vector v; should_be_lvalue(true ? rvalue_probe<vector>(v) : v); // Error } //--- ^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/50835] [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template 2011-10-23 2:10 [Bug c++/50835] New: [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template mimomorin at gmail dot com 2011-10-23 11:47 ` [Bug c++/50835] " daniel.kruegler at googlemail dot com 2011-10-23 11:50 ` daniel.kruegler at googlemail dot com @ 2011-10-23 12:24 ` daniel.kruegler at googlemail dot com 2011-10-27 9:23 ` rguenth at gcc dot gnu.org ` (3 subsequent siblings) 6 siblings, 0 replies; 8+ messages in thread From: daniel.kruegler at googlemail dot com @ 2011-10-23 12:24 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50835 --- Comment #3 from Daniel Krügler <daniel.kruegler at googlemail dot com> 2011-10-23 12:23:41 UTC --- Removing as much templates as possible: //--- struct A {}; struct B { explicit B(A &t) : value(t) {} operator A&() const { return value; } A& value; }; void should_be_lvalue(A&) { } template <typename> void f() { A v; should_be_lvalue(true ? B(v) : v); } //--- This code is still rejected in either C++03 or C++11 mode: "error: invalid initialization of non-const reference of type 'A&' from an rvalue of type 'A'" "error: in passing argument 1 of 'void should_be_lvalue(A&)'" ^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/50835] [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template 2011-10-23 2:10 [Bug c++/50835] New: [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template mimomorin at gmail dot com ` (2 preceding siblings ...) 2011-10-23 12:24 ` daniel.kruegler at googlemail dot com @ 2011-10-27 9:23 ` rguenth at gcc dot gnu.org 2011-10-27 11:36 ` rguenth at gcc dot gnu.org ` (2 subsequent siblings) 6 siblings, 0 replies; 8+ messages in thread From: rguenth at gcc dot gnu.org @ 2011-10-27 9:23 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50835 Richard Guenther <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|--- |4.7.0 ^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/50835] [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template 2011-10-23 2:10 [Bug c++/50835] New: [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template mimomorin at gmail dot com ` (3 preceding siblings ...) 2011-10-27 9:23 ` rguenth at gcc dot gnu.org @ 2011-10-27 11:36 ` rguenth at gcc dot gnu.org 2011-11-08 17:14 ` jason at gcc dot gnu.org 2011-11-08 17:31 ` jason at gcc dot gnu.org 6 siblings, 0 replies; 8+ messages in thread From: rguenth at gcc dot gnu.org @ 2011-10-27 11:36 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50835 Richard Guenther <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |rejects-valid Priority|P3 |P1 Status|UNCONFIRMED |NEW Last reconfirmed| |2011-10-27 Known to work| |4.6.2 Ever Confirmed|0 |1 --- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-10-27 11:35:18 UTC --- Confirmed. EDG also accepts this. ^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/50835] [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template 2011-10-23 2:10 [Bug c++/50835] New: [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template mimomorin at gmail dot com ` (4 preceding siblings ...) 2011-10-27 11:36 ` rguenth at gcc dot gnu.org @ 2011-11-08 17:14 ` jason at gcc dot gnu.org 2011-11-08 17:31 ` jason at gcc dot gnu.org 6 siblings, 0 replies; 8+ messages in thread From: jason at gcc dot gnu.org @ 2011-11-08 17:14 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50835 --- Comment #5 from Jason Merrill <jason at gcc dot gnu.org> 2011-11-08 17:10:16 UTC --- Author: jason Date: Tue Nov 8 17:10:09 2011 New Revision: 181174 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181174 Log: PR c++/50835 * typeck.c (build_x_conditional_expr): Preserve lvalue/xvalueness. * tree.c (lvalue_kind) [NON_DEPENDENT_EXPR]: Return clk_ordinary in C++98. Added: trunk/gcc/testsuite/g++.dg/template/lvalue2.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/tree.c trunk/gcc/cp/typeck.c trunk/gcc/testsuite/ChangeLog ^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug c++/50835] [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template 2011-10-23 2:10 [Bug c++/50835] New: [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template mimomorin at gmail dot com ` (5 preceding siblings ...) 2011-11-08 17:14 ` jason at gcc dot gnu.org @ 2011-11-08 17:31 ` jason at gcc dot gnu.org 6 siblings, 0 replies; 8+ messages in thread From: jason at gcc dot gnu.org @ 2011-11-08 17:31 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50835 Jason Merrill <jason at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |FIXED --- Comment #6 from Jason Merrill <jason at gcc dot gnu.org> 2011-11-08 17:28:58 UTC --- Fixed. ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2011-11-08 17:30 UTC | newest] Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2011-10-23 2:10 [Bug c++/50835] New: [4.7 Regression] Lvalue-ness of conditional operator results is incorrect in a function template mimomorin at gmail dot com 2011-10-23 11:47 ` [Bug c++/50835] " daniel.kruegler at googlemail dot com 2011-10-23 11:50 ` daniel.kruegler at googlemail dot com 2011-10-23 12:24 ` daniel.kruegler at googlemail dot com 2011-10-27 9:23 ` rguenth at gcc dot gnu.org 2011-10-27 11:36 ` rguenth at gcc dot gnu.org 2011-11-08 17:14 ` jason at gcc dot gnu.org 2011-11-08 17:31 ` jason at gcc dot gnu.org
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