https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104537
Bug ID: 104537
Summary: ICE when generic-lambda as function parameter fails to
be converted to pointer to function
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: nickhuang99 at hotmail dot com
Target Milestone: ---
Consider this invalid conversion for this generic-lambda to pointer to function
which is defined by "decltype(+[](T&& t )->T{return t+1;}".
This ICE happens when original accepted parameter type changed from "T" to
"T&&".
See compiler explorer (https://www.godbolt.org/z/fde1bc3zE)
I suspect this is some related issue with another unconfirmed case PR104358.
template<typename T>
auto foo(T&& t, decltype(+[](T&& t )->T{return t+1;}) lam){
return lam(t);
}
void test(){
foo<int>(5, [](int t){return t+1;});
}
<source>:8:21: error: invalid user-defined conversion from
'test()::<lambda(int)>' to 'int (*)(int&&)' [-fpermissive]
8 | foo<int>(5, [](int t){return t+1;});
| ^~~~~~~~~~~~~~~~~~~~~~
...
internal compiler error: error reporting routines re-entered.
0x2174365 warning_at(unsigned int, int, char const*, ...)
...
