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* [Bug c++/108736] New: pconcepts] multidimensional subscript operator reports invalid error in requires test
@ 2023-02-09 7:25 ldalessandro at gmail dot com
2023-02-09 18:51 ` [Bug c++/108736] [concepts] multidimensional subscript operator inside requires with variable template arguments is broken pinskia at gcc dot gnu.org
2023-09-24 18:52 ` ppalka at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: ldalessandro at gmail dot com @ 2023-02-09 7:25 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108736
Bug ID: 108736
Summary: pconcepts] multidimensional subscript operator reports
invalid error in requires test
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ldalessandro at gmail dot com
Target Milestone: ---
The following code produces an error when evaluating the concept.
auto foo(auto a, auto... i) -> decltype(auto) {
if constexpr (requires { a[i...]; }) {
return a[i...];
}
else {
return a;
}
}
int x = foo(1);
> <source>: In instantiation of 'decltype(auto) foo(auto:1, auto:2 ...) [with auto:1 = int; auto:2 = {}]':
> <source>:10:12: required from here
> <source>:2:31: error: built-in subscript operator without expression list
> 2 | if constexpr (requires { a[i...]; }) {
> | ~^
> Compiler returned: 1
Workaround: specialize on sizeof...(i) to avoid this test when i... is empty.
Live example: https://godbolt.org/z/K3oezd1qz
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug c++/108736] [concepts] multidimensional subscript operator inside requires with variable template arguments is broken 2023-02-09 7:25 [Bug c++/108736] New: pconcepts] multidimensional subscript operator reports invalid error in requires test ldalessandro at gmail dot com @ 2023-02-09 18:51 ` pinskia at gcc dot gnu.org 2023-09-24 18:52 ` ppalka at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: pinskia at gcc dot gnu.org @ 2023-02-09 18:51 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108736 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|[concepts] multidimensional |[concepts] multidimensional |subscript operator reports |subscript operator inside |invalid error in requires |requires with variable |test |template arguments is | |broken Status|UNCONFIRMED |NEW Ever confirmed|0 |1 Last reconfirmed| |2023-02-09 --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Confirmed, even this is rejected: ``` auto foo(auto a, auto... i) -> decltype(auto) { if constexpr (requires { a[i...]; }) { return a[i...]; } else { return a; } } int x = foo(1, 1); ``` Note clang just ICEs. Also the above works if it is not a variable argument auto ... That is: ``` template<typename T, typename T1> auto foo(T a, T1 i) { if constexpr (requires { a[i]; }) { return a[i]; } else { return a; } } int x = foo(1, 1); ``` Compiles just fine. ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug c++/108736] [concepts] multidimensional subscript operator inside requires with variable template arguments is broken 2023-02-09 7:25 [Bug c++/108736] New: pconcepts] multidimensional subscript operator reports invalid error in requires test ldalessandro at gmail dot com 2023-02-09 18:51 ` [Bug c++/108736] [concepts] multidimensional subscript operator inside requires with variable template arguments is broken pinskia at gcc dot gnu.org @ 2023-09-24 18:52 ` ppalka at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: ppalka at gcc dot gnu.org @ 2023-09-24 18:52 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108736 Patrick Palka <ppalka at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |DUPLICATE CC| |ppalka at gcc dot gnu.org --- Comment #2 from Patrick Palka <ppalka at gcc dot gnu.org> --- dup of the recently fixed PR111493 *** This bug has been marked as a duplicate of bug 111493 *** ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-09-24 18:52 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-02-09 7:25 [Bug c++/108736] New: pconcepts] multidimensional subscript operator reports invalid error in requires test ldalessandro at gmail dot com 2023-02-09 18:51 ` [Bug c++/108736] [concepts] multidimensional subscript operator inside requires with variable template arguments is broken pinskia at gcc dot gnu.org 2023-09-24 18:52 ` ppalka at gcc dot gnu.org
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