https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63872
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Smaller testcase:
template<typename T>
T make()
{
return { typename T::type{0} };
}
void f()
{
struct X {
using type = int;
X(int) { }
};
make<X>();
}
local.cc: In function ‘void f()’:
local.cc:10:21: warning: typedef ‘using type = int’ locally defined but not
used [-Wunused-local-typedefs]
using type = int;
^
As stated in comment 0, this causes warnings for types with 'allocator_type' or
'is_transparent' typedefs, which get used indirectly by standard library
components and removing them would still compile but with different semantics.
Adding __attribute__((unused)) or [[maybe_unused]] does work, but shouldn't be
necessary.
