https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111803
Bug ID: 111803
Summary: Template deduction failure for baseclass member
pointer with template data type
Product: gcc
Version: 13.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: grbrown93 at sbcglobal dot net
Target Milestone: ---
Compiler error tested on versions 4.4, 6.1, 7.1, 10.1, 12.1, 13.2
Compiles fine on icpc and MSVC
> g++ test.cpp -o test
error: no matching function for call to 'Container<B>::print(float A::*)'
It should be trying to call 'Container<B>::print(float B::*)' but it's deducing
'A' from the 'data' member rather than 'B' from the 'ClassType' template arg.
Weirdly, it gets the correct call when using 'template print<float>' though
(guess that makes it follow a simpler logic path?).
Reproducible sample:
template<typename ClassType>
class Container
{
public:
template<typename DataType>
void print(DataType ClassType::*member)
{
}
};
class A
{
public:
float data;
template<typename ClassType>
static void setup(Container<ClassType>& container)
{
container.print(&ClassType::data); // BROKEN IN GCC!
container.template print<float>(&ClassType::data); //
WORKAROUND
container.print((float ClassType::*)&ClassType::data); //
WORKAROUND
}
};
class B : public A
{
public:
double data2;
template<typename ClassType>
static void setup(Container<ClassType>& container)
{
A::setup(container);
container.print(&ClassType::data2); // WORKS FINE
}
};
int main()
{
Container<B> container;
B::setup(container);
return 0;
}
