https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79698
Bug ID: 79698
Summary: spurious -Wunused-local-typedefs on a typedef used by
a template
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
GCC issues the -Wunused-local-typedefs warning for the typedef defined in
struct B in the function template f() below even though the typedef is used.
Clang handles this case correctly.
$ cat t.C && gcc -S -Wall -Wextra -Wpedantic -Wunused-local-typedefs t.C
template <class T>
struct A {
typedef typename T::U U;
U u;
};
template <class T>
T f ()
{
struct B {
typedef T U;
};
return typename A<B>::U ();
}
t.C: In function ‘T f()’:
t.C:11:15: warning: typedef ‘f()::B::U’ locally defined but not used
[-Wunused-local-typedefs]
typedef T U;
^
