https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101921
Bug ID: 101921
Summary: G++ cannot find a template function with lambda as
default template argument
Product: gcc
Version: 11.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: fchelnokov at gmail dot com
Target Milestone: ---
Compilation of this valid code:
```
template<class T = decltype([]{})> void bar() {}
void foo(auto) { bar(); }
```
results in error:
```
error: no matching function for call to 'bar()'
2 | void foo(auto) { bar(); }
| ~~~^~
note: candidate: 'template<class T> void bar()'
1 | template<class T = decltype([]{})> void bar() {}
| ^~~
note: template argument deduction/substitution failed:
```
Other compilers accept it: https://gcc.godbolt.org/z/9GsPo8Pnb
