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* [Bug c++/105511] New: Spurious warning: "expected 'template' keyword..." when lt and gt compare over ternary
@ 2022-05-06 23:50 cuzdav at gmail dot com
2022-10-31 1:45 ` [Bug c++/105511] [12/13 Regression] " pinskia at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: cuzdav at gmail dot com @ 2022-05-06 23:50 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105511
Bug ID: 105511
Summary: Spurious warning: "expected 'template' keyword..."
when lt and gt compare over ternary
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: cuzdav at gmail dot com
Target Milestone: ---
Only on g++ 12 (new warning).
Building with the freshly released G++12 with warning enabled
(-Werror=missing-template-keyword)
Complete, minimized code:
template <typename X>
bool before(bool ascending, X & a, X * b) {
return ascending ? a.value < (*b).value : a.value > (*b).value;
}
<source>:4:26: warning: expected 'template' keyword before dependent template
name [-Wmissing-template-keyword]
4 | return ascending ? a.value < (*b).value : a.value > (*b).value;
| ^~~~~
Visible on Compiler Explorer
https://godbolt.org/z/dW9hjbdex
Yes, the left-angle and right-angle brackets are present, but it's not looking
quite hard enough to see that they are on opposite sides of a ternary ':'.
My Compiler, if it matters:
/opt/imc/gcc-12.1.0/bin/g++
(base) bash-4.2$ g++ -v
Using built-in specs.
COLLECT_GCC=g++
COLLECT_LTO_WRAPPER=/opt/imc/gcc-12.1.0/libexec/gcc/x86_64-pc-linux-gnu/12.1.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: ../gcc-12.1.0/configure --prefix=/opt/imc/gcc-12.1.0
--enable-languages=c,c++,fortran,lto --disable-multilib
--with-build-time-tools=/home/trading/cuzdav/code/imc-gcc/gcc/12.1.0/INSTALLDIR//opt/imc/gcc-12.1.0/bin
--enable-libstdcxx-time=rt
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.1.0 (GCC)
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/105511] [12/13 Regression] Spurious warning: "expected 'template' keyword..." when lt and gt compare over ternary
2022-05-06 23:50 [Bug c++/105511] New: Spurious warning: "expected 'template' keyword..." when lt and gt compare over ternary cuzdav at gmail dot com
@ 2022-10-31 1:45 ` pinskia at gcc dot gnu.org
2022-10-31 20:43 ` mpolacek at gcc dot gnu.org
2022-12-20 13:42 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-10-31 1:45 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105511
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Known to work| |11.1.0, 11.3.0
Summary|Spurious warning: "expected |[12/13 Regression] Spurious
|'template' keyword..." when |warning: "expected
|lt and gt compare over |'template' keyword..." when
|ternary |lt and gt compare over
| |ternary
Known to fail| |12.1.0
Target Milestone|--- |12.3
Ever confirmed|0 |1
Last reconfirmed| |2022-10-31
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed.
r12-6563-gb8ffa71e4271ae introduced the warning and enabled it by default.
I say this is a regression since the warning is enabled by default and I can't
even see how to avoid the warning.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/105511] [12/13 Regression] Spurious warning: "expected 'template' keyword..." when lt and gt compare over ternary
2022-05-06 23:50 [Bug c++/105511] New: Spurious warning: "expected 'template' keyword..." when lt and gt compare over ternary cuzdav at gmail dot com
2022-10-31 1:45 ` [Bug c++/105511] [12/13 Regression] " pinskia at gcc dot gnu.org
@ 2022-10-31 20:43 ` mpolacek at gcc dot gnu.org
2022-12-20 13:42 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: mpolacek at gcc dot gnu.org @ 2022-10-31 20:43 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105511
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |mpolacek at gcc dot gnu.org
--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
I'm not sure if there's anything to fix; the manual says:
In rare cases it is possible to get false positives. To silence this, wrap
the expression in parentheses. For example, the following is treated as a
template, even where m and N are integers:
@smallexample
void NotATemplate (my_class t)
@{
int N = 5;
bool test = t.m < N > (0); // Treated as a template.
test = (t.m < N) > (0); // Same meaning, but not treated as a template.
@}
@end smallexample
so
return ascending ? (a.value < (*b).value) : a.value > (*b).value;
prevents the warning.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/105511] [12/13 Regression] Spurious warning: "expected 'template' keyword..." when lt and gt compare over ternary
2022-05-06 23:50 [Bug c++/105511] New: Spurious warning: "expected 'template' keyword..." when lt and gt compare over ternary cuzdav at gmail dot com
2022-10-31 1:45 ` [Bug c++/105511] [12/13 Regression] " pinskia at gcc dot gnu.org
2022-10-31 20:43 ` mpolacek at gcc dot gnu.org
@ 2022-12-20 13:42 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2022-12-20 13:42 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105511
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution|--- |WONTFIX
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
So indeed it works as documented, thus WONTFIX.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-12-20 13:42 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2022-05-06 23:50 [Bug c++/105511] New: Spurious warning: "expected 'template' keyword..." when lt and gt compare over ternary cuzdav at gmail dot com
2022-10-31 1:45 ` [Bug c++/105511] [12/13 Regression] " pinskia at gcc dot gnu.org
2022-10-31 20:43 ` mpolacek at gcc dot gnu.org
2022-12-20 13:42 ` rguenth at gcc dot gnu.org
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