https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83672
Bug ID: 83672
Summary: Unable to take the address of a template function
parameter pack specialization with a function argument
Product: gcc
Version: 7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: smw at gcc dot gnu.org
Target Milestone: ---
Can't take the address of a template function specialization if the template
function has a parameter pack and one of the arguments to the parameter pack
expansion is a function type-id.
Without resorting to further word torture, an example might clarify.
template <typename ...PP>
void f01(PP...)
{ }
int f00() { return 0; }
int
main()
{
f01<int()>(f00); // OK, call specialization
void (*fp01)(int) = f01<int>; // OK, address of int specialization
void (*fp02)(int()) = f01<int(*)()>; // compiles OK, but, um...
void (*fp03)(int()) = f01<int()>; // nope nope nope
}
14 : <source>:14:25: error: no matches converting function 'f01' to type 'void
(*)(int (*)())'
void (*fp03)(int()) = f01<int()>; // nope nope nope
^~~~~~~~~~
2 : <source>:2:8: note: candidate is: template<class ... PP> void f01(PP ...)
void f01(PP...)
^~~
Please note that clang5 and ICC18 both accept this code.
