https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115339
Bug ID: 115339
Summary: Missing -Wpedantic warning for a declarative
nested-name-specifier with a decltype-specifier.
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: email at miropalmu dot cc
Target Milestone: ---
Following compiles on a GCC 15.0.0 20240604 without warnings with flags
-std=c++26 -Wall -Wextra -Wpedantic (https://godbolt.org/z/6fdbo9YcW):
```
struct X {
struct a;
};
auto x = X{};
struct decltype(x)::a{};
```
However it should be ill-formed or at least give warning with -Wpedantic,
as [expr.prim.id.general] states (https://eel.is/c++draft/expr.prim.id#qual-2):
> A declarative nested-name-specifier shall not have a decltype-specifier.
`decltype(x)` is declarative nested-name-specifier as it is part of
class-head-name.
