http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48518
Summary: Inconsistent instantiation behavior depending on
operator overloading
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: jyass...@gcc.gnu.org
The following program instantiates wrap<Undefined>, but a very similar program
that doesn't call an overloaded operator doesn't:
$ cat test.ii
template <class C> struct scoped_ptr {
C& operator*() const {
return *ptr_;
}
C* ptr_;
};
template<class T> struct wrap {
T must_be_complete;
};
class Undefined;
struct S {
wrap<Undefined> &content() const {
return *content_;
}
scoped_ptr<wrap<Undefined> > content_;
};
$ trunk/g++ -c test.ii
test.ii: In instantiation of ‘wrap<Undefined>’:
test.ii:13:13: instantiated from here
test.ii:8:5: error: ‘wrap<T>::must_be_complete’ has incomplete type
test.ii:10:7: error: forward declaration of ‘struct Undefined’
$
However:
$ cat test_works.ii
template <class C> struct scoped_ptr {
C& get() const {
return *ptr_;
}
C* ptr_;
};
template<class T> struct wrap {
T must_be_complete;
};
class Undefined;
struct S {
wrap<Undefined> &content() const {
return content_.get();
}
scoped_ptr<wrap<Undefined> > content_;
};
$ ~/opensource/gcc/git/install/bin/g++ -c test_works.ii
$
This was a change from gcc-4.4 to gcc-4.5. Comeau agrees with gcc here, but
clang disagrees.
This is confusing because the operator that makes a difference is on
scoped_ptr<wrap<Undefined>>, not on wrap<Undefined>.
