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* [Bug c++/59701] New: A variadic alias template aliasing another variadic alias template doesn't work
@ 2014-01-06 15:17 ville.voutilainen at gmail dot com
2014-01-10 20:34 ` [Bug c++/59701] " ville.voutilainen at gmail dot com
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: ville.voutilainen at gmail dot com @ 2014-01-06 15:17 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59701
Bug ID: 59701
Summary: A variadic alias template aliasing another variadic
alias template doesn't work
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ville.voutilainen at gmail dot com
template<typename... Args> struct foo { };
template<typename T, typename... Args> using bar = foo<T, Args...>;
template<typename T, typename... Args> using baz = bar<Args..., T>;
int
main (int argc, char *argv[])
{
}
This gives
edoceo7.cpp: In substitution of ‘template<class T, class ... Args> using bar =
foo<T, Args ...> [with T = Args ...; Args = {<expression error>}]’:
edoceo7.cpp:3:66: required from here
edoceo7.cpp:2:67: error: template argument 2 is invalid
template<typename T, typename... Args> using bar = foo<T, Args...>;
^
Multiple clang versions accept the code. Some clang versions ICE on it, but
that's another matter. :)
>From gcc-bugs-return-439399-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Mon Jan 06 15:35:33 2014
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From: "ville.voutilainen at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/59702] New: Infinite recursion in a late-specified return type of a function template
Date: Mon, 06 Jan 2014 15:35:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59702
Bug ID: 59702
Summary: Infinite recursion in a late-specified return type of
a function template
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ville.voutilainen at gmail dot com
struct A {};
template<typename>
int func (A) {
return {};
}
template<typename T>
auto func () -> decltype (func<T> (A{})) {
return {};
}
int
main (int argc, char *argv[])
{
func<int> ();
}
Result:
edoceo8.cpp:9:39: error: template instantiation depth exceeds maximum of 900
(use -ftemplate-depth= to increase the maximum) substituting ‘template<class T>
decltype (func<T>(A{})) func() [with T = int]’
auto func () -> decltype (func<T> (A{})) {
^
edoceo8.cpp:9:39: recursively required by substitution of ‘template<class T>
decltype (func<T>(A{})) func() [with T = int]’
edoceo8.cpp:9:39: required by substitution of ‘template<class T> decltype
(func<T>(A{})) func() [with T = int]’
edoceo8.cpp:16:14: required from here
edoceo8.cpp: In function ‘int main(int, char**)’:
edoceo8.cpp:16:14: error: no matching function for call to ‘func()’
func<int> ();
^
edoceo8.cpp:16:14: note: candidates are:
edoceo8.cpp:4:5: note: template<class> int func(A)
int func (A) {
^
edoceo8.cpp:4:5: note: template argument deduction/substitution failed:
edoceo8.cpp:16:14: note: candidate expects 1 argument, 0 provided
func<int> ();
^
edoceo8.cpp:9:6: note: template<class T> decltype (func<T>(A{})) func()
auto func () -> decltype (func<T> (A{})) {
^
edoceo8.cpp:9:6: note: substitution of deduced template arguments resulted in
errors seen above
It doesn't seem to me like the late-specified return type is even referring to
the return type of the latter function template.
>From gcc-bugs-return-439400-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Mon Jan 06 15:44:12 2014
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From: "ville.voutilainen at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/59702] Infinite recursion in a late-specified return type of a function template
Date: Mon, 06 Jan 2014 15:44:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?idY702
--- Comment #1 from Ville Voutilainen <ville.voutilainen at gmail dot com> ---
I forgot to mention that clang accepts the code.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-08-23 6:40 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-01-06 15:17 [Bug c++/59701] New: A variadic alias template aliasing another variadic alias template doesn't work ville.voutilainen at gmail dot com
2014-01-10 20:34 ` [Bug c++/59701] " ville.voutilainen at gmail dot com
2015-03-18 20:22 ` [Bug c++/59701] [DR 1430] " paolo.carlini at oracle dot com
2021-08-23 6:40 ` pinskia at gcc dot gnu.org
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