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* [Bug c++/113629] New: 'deducing this' does not work with conversion operators
@ 2024-01-27 17:01 hewillk at gmail dot com
2024-01-27 17:02 ` [Bug c++/113629] " hewillk at gmail dot com
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: hewillk at gmail dot com @ 2024-01-27 17:01 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113629
Bug ID: 113629
Summary: 'deducing this' does not work with conversion
operators
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: hewillk at gmail dot com
Target Milestone: ---
It seems that GCC's deducing this implementation has some issues with derived
classes that inherit from a base class that has conversion operators:
struct Base {
operator int(this auto&&) {
return 42;
}
};
struct Derived : Base {};
int main() {
Derived derived;
return static_cast<int>(derived);
}
GCC rejects the above code with:
<source>:11:10: error: invalid 'static_cast' from type 'Derived' to type 'int'
11 | return static_cast<int>(derived);
| ^~~~~~~~~~~~~~~~~~~~~~~~~
which seems wrong.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/113629] 'deducing this' does not work with conversion operators
2024-01-27 17:01 [Bug c++/113629] New: 'deducing this' does not work with conversion operators hewillk at gmail dot com
@ 2024-01-27 17:02 ` hewillk at gmail dot com
2024-01-27 17:24 ` hewillk at gmail dot com
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: hewillk at gmail dot com @ 2024-01-27 17:02 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113629
--- Comment #1 from 康桓瑋 <hewillk at gmail dot com> ---
test:
https://godbolt.org/z/jdz3ejohv
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/113629] 'deducing this' does not work with conversion operators
2024-01-27 17:01 [Bug c++/113629] New: 'deducing this' does not work with conversion operators hewillk at gmail dot com
2024-01-27 17:02 ` [Bug c++/113629] " hewillk at gmail dot com
@ 2024-01-27 17:24 ` hewillk at gmail dot com
2024-03-06 9:49 ` cvs-commit at gcc dot gnu.org
2024-03-06 9:50 ` nshead at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: hewillk at gmail dot com @ 2024-01-27 17:24 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113629
--- Comment #2 from 康桓瑋 <hewillk at gmail dot com> ---
more reduced:
struct Base {
operator int(this auto&&) {
return 42;
}
};
int main() {
Base b;
// return static_cast<int>(Base{}); // ok
return static_cast<int>(b); // error
}
https://godbolt.org/z/qGrbf4rj7
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/113629] 'deducing this' does not work with conversion operators
2024-01-27 17:01 [Bug c++/113629] New: 'deducing this' does not work with conversion operators hewillk at gmail dot com
2024-01-27 17:02 ` [Bug c++/113629] " hewillk at gmail dot com
2024-01-27 17:24 ` hewillk at gmail dot com
@ 2024-03-06 9:49 ` cvs-commit at gcc dot gnu.org
2024-03-06 9:50 ` nshead at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2024-03-06 9:49 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113629
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Nathaniel Shead <nshead@gcc.gnu.org>:
https://gcc.gnu.org/g:49d83e963aa453600088380aebd507e172eb80ad
commit r14-9332-g49d83e963aa453600088380aebd507e172eb80ad
Author: Nathaniel Shead <nathanieloshead@gmail.com>
Date: Wed Mar 6 00:43:22 2024 +1100
c++: Fix template deduction for conversion operators with xobj parameters
[PR113629]
Unification for conversion operators (DEDUCE_CONV) doesn't perform
transformations like handling forwarding references. This is correct in
general, but not for xobj parameters, which should be handled "normally"
for the purposes of deduction: [temp.deduct.conv] only applies to the
return type of the conversion function.
PR c++/113629
gcc/cp/ChangeLog:
* pt.cc (type_unification_real): Only use DEDUCE_CONV for the
return type of a conversion function.
gcc/testsuite/ChangeLog:
* g++.dg/cpp23/explicit-obj-conv-op.C: New test.
Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>
Reviewed-by: Jason Merrill <jason@redhat.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug c++/113629] 'deducing this' does not work with conversion operators
2024-01-27 17:01 [Bug c++/113629] New: 'deducing this' does not work with conversion operators hewillk at gmail dot com
` (2 preceding siblings ...)
2024-03-06 9:49 ` cvs-commit at gcc dot gnu.org
@ 2024-03-06 9:50 ` nshead at gcc dot gnu.org
3 siblings, 0 replies; 5+ messages in thread
From: nshead at gcc dot gnu.org @ 2024-03-06 9:50 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113629
Nathaniel Shead <nshead at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |14.0
Assignee|unassigned at gcc dot gnu.org |nshead at gcc dot gnu.org
Resolution|--- |FIXED
CC| |nshead at gcc dot gnu.org
Status|UNCONFIRMED |RESOLVED
--- Comment #4 from Nathaniel Shead <nshead at gcc dot gnu.org> ---
Fixed.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-03-06 9:50 UTC | newest]
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2024-01-27 17:01 [Bug c++/113629] New: 'deducing this' does not work with conversion operators hewillk at gmail dot com
2024-01-27 17:02 ` [Bug c++/113629] " hewillk at gmail dot com
2024-01-27 17:24 ` hewillk at gmail dot com
2024-03-06 9:49 ` cvs-commit at gcc dot gnu.org
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