can a sender's connect member fn be private if it befriends execution::connect_t? #342
Description
can a user expect this to work?
#include <execution>
struct Sender
{
using sender_concept = std::execution::sender_t;
private:
friend std::execution::connect_t;
auto connect( std::execution::receiver auto rcvr )
{
//...
}
};
int main()
{
auto op = std::execution::connect(Sender{}, SomeReceiver{});
}the current wording suggests it should work but it is not guaranteed. should it be?
same question about get_env and get_completion_signatures — although the latter is complicated by the fact that there is no get_completion_signatures_t to befriend.