https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110211
Bug ID: 110211
Summary: Local lambda treated as non-local
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Keywords: c++-lambda, rejects-valid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: johelegp at gmail dot com
CC: johelegp at gmail dot com
Target Milestone: ---
See <https://compiler-explorer.com/z/W9PzEcc1v>.
```C++
template<class F, class T> concept invocable = requires(F f, T x) { f(x); };
static_assert(!invocable<
decltype([]<class T>(T) -> decltype([&]<class U>(U x)
requires requires { x.a();
}
{}(T())) {}),
int>);
```
```output
<source>:3:52: error: non-local lambda expression cannot have a capture-default
3 | decltype([]<class T>(T) -> decltype([&]<class U>(U x)
| ^
Compiler returned: 1
```
According to <https://eel.is/c++draft/expr.prim.lambda#capture-3>, this should
work.
If the `static_assert` is in a function, it still fails:
<https://compiler-explorer.com/z/b7rdqfxed>.
It fails on GCC10: <https://compiler-explorer.com/z/znsYvKdz1>.
