https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122256
Bug ID: 122256
Summary: ICE: unexpected expression ‘One` of kind
template_parm_index/Segmentation Fault from base
method in constraint
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: chris at pcserenity dot com
Target Milestone: ---
Created attachment 62543
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=62543&action=edit
.out/.ii of code form one (template_parm_index)
Occurs on trunk.
There are two variants of this that I believe to be related. The first is the
furthest I could reduce the MRE while still keeping the overall code the same
as the original in which I encountered the bug. The second, is slightly closer
to the original in that Foo is a template struct, which results an a
segmentation fault instead of "unexpected expression ‘One’ of kind
template_parm_index".
May relate to 120041.
Command (excluding bug reporting specific switches): -std=c++20 -c input.cpp
First:
------
CE: https://godbolt.org/z/zfK8Goj9M
--------------- BEGIN SNIPPET ONE (template_param_index)
-------------------------
struct Bar {
static consteval bool enabled(int) { return true; }
};
template <int One, int Two>
struct Baz : Bar {
Baz() requires(enabled(Two)) {}
};
int main() {
Baz<4, 5> baz{};
}
------------------------------- END SNIPPET ONE
----------------------------------
Second:
-------
CE: https://godbolt.org/z/n81WKrTdx
----------------- BEGIN SNIPPET TWO (segmentation fault)
-----------------------
template<int N>
struct Foo {};
struct Bar {
static consteval bool enabled(int) { return true; }
};
template <Foo One, int Two>
struct Baz : Bar {
Baz() requires(enabled(Two)) {}
};
int main() {
Baz<Foo<4>{}, 5> baz{};
}
------------------------------- END SNIPPET TWO
----------------------------------
