proposal: fmt: %p should accept uintptr #41495
Description
What version of Go are you using (go version)?
1.15
Does this issue reproduce with the latest release?
y
What operating system and processor architecture are you using (go env)?
N/A
What did you do?
fmt.Printf("%p", stringHeader.Data)
What did you expect to see?
A pointer value.
What did you see instead?
A fmt warning that %p got a non-pointer.
Rationale: It's true that uintptr is an integer-like thing rather than a pointer-like thing, but it's explicitly the type of integer which is used to represent pointers. It's certainly possible to just add the extra conversion everywhere, but I don't think it makes anything clearer, safer, or better. Allowing %p for uintptr shouldn't break any code except possibly "tests that check for getting that diagnostic" which seems like an edge case.
In the absence of moving GC, etc, I'd want %p to print a uintptr and the corresponding unsafe.Pointer identically.
(As a secondary issue, I would also sort of like %p to work on strings, printing the address of their backing store, but I'm enough less convinced of that that I'm leaving it as a parenthetical.)