http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57573
Bug ID: 57573
Summary: [C++1y] bogus "taking address of temporary" error
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Keywords: rejects-valid
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
struct A { };
struct B { A a; };
void f(A*) { }
template<class T>
void g()
{
B b;
f(&(b.a));
}
This compiles OK with -std=c++98 or -std=c++11 but not -std=c++1y:
$ g++11 f.cc -std=c++1y -c
f.cc: In function ‘void g()’:
f.cc:10:10: error: taking address of temporary [-fpermissive]
f(&(b.a));
^
It also compiles OK if g() is not a template.
This causes an error in <mutex> in C++1y mode:
/home/redi/gcc/4.x/include/c++/4.9.0/mutex: In function ‘void
std::call_once(std::once_flag&, _Callable&&, _Args&& ...)’:
/home/redi/gcc/4.x/include/c++/4.9.0/mutex:786:48: error: lvalue required as
unary ‘&’ operand
int __e = __gthread_once(&(__once._M_once), &__once_proxy);
^
I don't know why those parentheses are there in <mutex> so they just can be
removed to fix the problem.
