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* [Bug c++/100997] New: [c++20] parse error when id-expression of constructor is simple-template-id
@ 2021-06-09 17:06 felix.morgner at gmail dot com
2021-06-09 17:12 ` [Bug c++/100997] " mpolacek at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: felix.morgner at gmail dot com @ 2021-06-09 17:06 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100997
Bug ID: 100997
Summary: [c++20] parse error when id-expression of constructor
is simple-template-id
Product: gcc
Version: 11.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: felix.morgner at gmail dot com
Target Milestone: ---
Created attachment 50972
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50972&action=edit
Example source file
In C++20 mode, GCC 11.1 rejects the following code:
template<typename>
struct A;
template<>
struct A<int> {
A<int>() {}
};
With the following error:
<source>:6:12: error: expected unqualified-id before ')' token
I currently don't have access to my copy of the standard, but working from both
https://wg21.link/std and https://wg21.link/std20, I am under the expression
that this code should be valid since:
According to [class.ctor], the sole id-expression of the ptr-declarator of the
ctors function declarator may be the injected-class-name. [class.pre] tells us
that the class-name of the class being declared is injected into scope of the
class, where it is called the injected-class-name. Moreover, [class.pre]
defines a class-name to be either an indentifier or a simnple-template-id. I
would argue that in the case of the explicit specialization above, A<int> would
be a simple-template-id and thus a valid injected-class-name.
The error does not occur in C++17 mode or in GCC prior to version 11.
Tested in all cases with "-Wall -Wextra -Werror -pedantic-errors"
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/100997] [c++20] parse error when id-expression of constructor is simple-template-id
2021-06-09 17:06 [Bug c++/100997] New: [c++20] parse error when id-expression of constructor is simple-template-id felix.morgner at gmail dot com
@ 2021-06-09 17:12 ` mpolacek at gcc dot gnu.org
2021-06-09 17:17 ` mpolacek at gcc dot gnu.org
2021-06-09 17:23 ` felix.morgner at gmail dot com
2 siblings, 0 replies; 4+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2021-06-09 17:12 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100997
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |mpolacek at gcc dot gnu.org
Resolution|--- |DUPLICATE
Status|UNCONFIRMED |RESOLVED
--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
This is C++20 DR 2237, disallow simple-template-id in cdtor: see
[diff.cpp17.class]p2.
The diagnostic should be improved, we have bug 97202 for that.
*** This bug has been marked as a duplicate of bug 97202 ***
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/100997] [c++20] parse error when id-expression of constructor is simple-template-id
2021-06-09 17:06 [Bug c++/100997] New: [c++20] parse error when id-expression of constructor is simple-template-id felix.morgner at gmail dot com
2021-06-09 17:12 ` [Bug c++/100997] " mpolacek at gcc dot gnu.org
@ 2021-06-09 17:17 ` mpolacek at gcc dot gnu.org
2021-06-09 17:23 ` felix.morgner at gmail dot com
2 siblings, 0 replies; 4+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2021-06-09 17:17 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100997
--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
To make it work just remove the "<int>" in A<int>() {}.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/100997] [c++20] parse error when id-expression of constructor is simple-template-id
2021-06-09 17:06 [Bug c++/100997] New: [c++20] parse error when id-expression of constructor is simple-template-id felix.morgner at gmail dot com
2021-06-09 17:12 ` [Bug c++/100997] " mpolacek at gcc dot gnu.org
2021-06-09 17:17 ` mpolacek at gcc dot gnu.org
@ 2021-06-09 17:23 ` felix.morgner at gmail dot com
2 siblings, 0 replies; 4+ messages in thread
From: felix.morgner at gmail dot com @ 2021-06-09 17:23 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100997
--- Comment #3 from Felix Morgner <felix.morgner at gmail dot com> ---
Thank you for the quick response. I will file a bug report with Boost GIL.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-06-09 17:23 UTC | newest]
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2021-06-09 17:06 [Bug c++/100997] New: [c++20] parse error when id-expression of constructor is simple-template-id felix.morgner at gmail dot com
2021-06-09 17:12 ` [Bug c++/100997] " mpolacek at gcc dot gnu.org
2021-06-09 17:17 ` mpolacek at gcc dot gnu.org
2021-06-09 17:23 ` felix.morgner at gmail dot com
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