[...] But I appreciate the other idea, is there any new contruct using arrow
notation? (the only thing Im aware of are trailing return types and
pointed-to structs).
C++17 added deduction guides:
template<class> struct S {};
S() -> S<int>;
C++20 added requires-expressions:
template<class> concept C = true;
bool b = requires { { 42 } -> C; };
But these are all rightward arrows -> using the existing arrow token; C++ has no token for leftward arrow <- and in fact introducing such a token would break the grammar of
template<int> struct A {};
A<-1> a;
HTH,
Arthur