if hasRType(n, n.RType, "RType") {
		return n.RType
	}
	return sliceElemRType(pos, n.X.Type())
}

// DeleteMapRType asserts that n is a "delete" operation, and returns
// an expression that yields the *runtime._type value representing the
// map type.
func DeleteMapRType(pos src.XPos, n *ir.CallExpr) ir.Node {
	assertOp(n, ir.ODELETE)
	if hasRType(n, n.RType, "RType") {
		return n.RType
	}

	map_ = walkExpr(map_, init)
	key = walkExpr(key, init)

	t := map_.Type()
	fast := mapfast(t)
	key = mapKeyArg(fast, n, key, false)
	return mkcall1(mapfndel(mapdelete[fast], t), nil, init, reflectdata.DeleteMapRType(base.Pos, n), map_, key)
}

// walkLenCap walks an OLEN or OCAP node.
func walkLenCap(n *ir.UnaryExpr, init *ir.Nodes) ir.Node {
	if isRuneCount(n) {