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* [Bug c++/68061] New: Can't use [[deprecated]] with requires clause
@ 2015-10-23 4:58 chrisb2244 at gmail dot com
2015-10-23 7:30 ` [Bug c++/68061] " chrisb2244 at gmail dot com
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: chrisb2244 at gmail dot com @ 2015-10-23 4:58 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68061
Bug ID: 68061
Summary: Can't use [[deprecated]] with requires clause
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: chrisb2244 at gmail dot com
Target Milestone: ---
Either of
template<ConceptName... parameter> requires RequiresConcept<A, parameter...>
const T x(const parameter... p) const { ... }
or
template<ConceptName... parameter, std::enable_if<...>
[[deprecated]] const T x(const parameter... p) const { ... }
will compile (using 'g++-trunk -std=c++1z ...')
Using the 'requires' clause along with an attempt to deprecate the function
using [[deprecated]] produces
"two consecutive '[' shall only introduce an attribute before '[' token"
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/68061] Can't use [[deprecated]] with requires clause
2015-10-23 4:58 [Bug c++/68061] New: Can't use [[deprecated]] with requires clause chrisb2244 at gmail dot com
@ 2015-10-23 7:30 ` chrisb2244 at gmail dot com
2021-08-05 10:30 ` redi at gcc dot gnu.org
2021-08-05 11:23 ` jakub at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: chrisb2244 at gmail dot com @ 2015-10-23 7:30 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68061
--- Comment #1 from Christian Butcher <chrisb2244 at gmail dot com> ---
Created attachment 36565
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36565&action=edit
Short compilable (or not) case showing problem
Commenting out the function definition for 'foo' allows compilation using
g++ -std=c++1z reqClauseDep.cpp -o Test
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/68061] Can't use [[deprecated]] with requires clause
2015-10-23 4:58 [Bug c++/68061] New: Can't use [[deprecated]] with requires clause chrisb2244 at gmail dot com
2015-10-23 7:30 ` [Bug c++/68061] " chrisb2244 at gmail dot com
@ 2021-08-05 10:30 ` redi at gcc dot gnu.org
2021-08-05 11:23 ` jakub at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: redi at gcc dot gnu.org @ 2021-08-05 10:30 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68061
--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This bug is still present on trunk when -fconcepts-ts is used, even in C++20
mode:
$ g++ -c 68061.C -std=c++20
$ g++ -c 68061.C -std=c++20 -fconcepts-ts
68061.C:3:1: error: two consecutive ‘[’ shall only introduce an attribute
before ‘[’ token
3 | [[deprecated]] void f(T);
| ^
It also affects [[nodiscard]] and so caused PR 101782.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/68061] Can't use [[deprecated]] with requires clause
2015-10-23 4:58 [Bug c++/68061] New: Can't use [[deprecated]] with requires clause chrisb2244 at gmail dot com
2015-10-23 7:30 ` [Bug c++/68061] " chrisb2244 at gmail dot com
2021-08-05 10:30 ` redi at gcc dot gnu.org
@ 2021-08-05 11:23 ` jakub at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: jakub at gcc dot gnu.org @ 2021-08-05 11:23 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68061
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jakub at gcc dot gnu.org
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
This is because with -fconcepts-ts the requires-clause argument is parsed as
logical-or-expression rather than constraint-logical-or-expression and for the
former the [ could be part of postfix-expression in there. Bet that is the
reason why constraint-logical-or-expression exists and allows only
primary-expressions mixed with ||s and &&s.
Perhaps the FE could have a hack, set some parser flag when parsing
requires-clause and in postfix-expression parsing if that flag is set instead
of the [[ error in there pretend [ is not there and ends the expression.
As a workaround,
template <class T>
requires true
void f [[deprecated]] (T);
works.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-08-05 11:23 UTC | newest]
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2015-10-23 4:58 [Bug c++/68061] New: Can't use [[deprecated]] with requires clause chrisb2244 at gmail dot com
2015-10-23 7:30 ` [Bug c++/68061] " chrisb2244 at gmail dot com
2021-08-05 10:30 ` redi at gcc dot gnu.org
2021-08-05 11:23 ` jakub at gcc dot gnu.org
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