http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55347
Bug #: 55347
Summary: Specialized member of class template prevents
visibility setting
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: [email protected]
ReportedBy: [email protected]
Compiling this code:
--- cut here ---
template<typename T>
class A
{
void func() {}
};
//#pragma GCC visibility push(default) -- no effect
template<> void A<int>::func() {} // This causes a problem
template class __attribute__((visibility("default"))) A<int>;
//#pragma GCC visibility pop
--- cut here ---
results in:
template_visibility.cc:10:55: warning: type attributes ignored after type is
already defined [-Wattributes]
The emitted code ends up hidden.
This is a minor issue in C++98 (I'm not sure why you'd want to do this), but
it's an actual problem in C++11: extern templates behave the same way.
I think that gcc's behavior is consistent, but there should be a way to
override the visibility of a particular class template specialization *without
instantiating/defining it*, then specialize a member, then instantiate the
template.
