Undocumented pointer type comparison operations?

[metagn]

There are overloads for < and <= in system defined on pointer, ptr T and ref T:

Nim/lib/system/comparisons.nim

Lines 124 to 126 in c4c44d1

	proc `<`*[T](x, y: ref T): bool {.magic: "LtPtr", noSideEffect.}
	proc `<`*[T](x, y: ptr T): bool {.magic: "LtPtr", noSideEffect.}
	proc `<`*(x, y: pointer): bool {.magic: "LtPtr", noSideEffect.}

Nim/lib/system/comparisons.nim

Lines 80 to 82 in c4c44d1

	proc `<=`*(x, y: bool): bool {.magic: "LeB", noSideEffect.}
	proc `<=`*[T](x, y: ref T): bool {.magic: "LePtr", noSideEffect.}
	proc `<=`*(x, y: pointer): bool {.magic: "LePtr", noSideEffect.}

But they have no documentation. Are these supposed to exist? Are they used anywhere?

[Araq]

They are supposed to exist so that e.g. a binary tree with pointer element type works. However, maybe it's a bad idea.

I think they are not used anywhere and binary trees lost against hash tables, pretty much.

[metagn]

For pointer it makes enough sense, for ref T and maybe ptr T it could be harmful though (for example, refactoring a, b: int to a, b: ref int, not realizing a < b needs to be a[] < b[])