https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109095
Bug ID: 109095
Summary: ICE when specializing a template with an auto nontype
template template parameter
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: n.morales.0 at proton dot me
Target Milestone: ---
This ICE is present in gcc 12.1/2 and in trunk:
template< typename T >
struct bar
{};
template< int X >
struct baz
{};
template< auto N, template< auto N2 > typename TT >
struct foo;
template< typename T, bar< T > B, template< T N2 > typename TT >
struct foo< B, TT >
{};
foo< bar< int >{}, baz > x;
This code ICE's with the following message when compiled with
-std=c++20 -Werror -Wall -Wextra
<source>:13:19: internal compiler error: in tsubst, at cp/pt.cc:15867
13 | struct foo< B, TT >
| ^
0x1bb069e internal_error(char const*, ...)
???:0
0x6ff396 fancy_abort(char const*, int, char const*)
???:0
0x884007 lookup_template_class(tree_node*, tree_node*, tree_node*, tree_node*,
int, int)
???:0
0x8aa461 finish_template_type(tree_node*, tree_node*, int)
???:0
0x861eaa c_parse_file()
???:0
0x93e4e5 c_common_parse_file()
???:0
I found a workaround to the ICE by making N2 "auto" instead of "T". Also, this
code compiles fine on clang 15.
Here is a godbolt link: https://godbolt.org/z/vxxeG36Gz
