https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107784
Bug ID: 107784
Summary: QOI: sizeof( bind_front( Member-Function ) ) too big
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: joerg.rich...@pdv-fs.de
Target Milestone: ---
Consider this example:
----8<----
cat > t.cc <<EOF
#include <iostream>
#include <functional>
struct Foo
{
void func()
{}
};
int main()
{
std::cout << sizeof( &Foo::func ) << std::endl;
std::cout << sizeof( std::bind_front( &Foo::func ) ) << std::endl;
}
EOF
g++ -v
g++ -std=c++20 -o t t.cc
t
----8<----
Outputs 16 and 24.
sizeof(Memberfunction) is 16.
sizeof(bind_front(Memberfunction)) is 24.
The resulting functor is too big to be stored inline in a std::function. It
would be nice if the trival case of bind_front is as big as the native
member-function-pointer.
