3 ms·
I've found that types like these normally come up in generic contexts, so the code I'm writing only usually deals with one layer of Option or Result until I get
by anonymoushn 3y ago
I've found that types like these normally come up in generic contexts, so the code I'm writing only usually deals with one layer of Option or Result until I get to the bit where I'm actually using the value and find out I have to write "try try foo();". That said, I think this sort of thing will do it:
const std = @import("std");
fn some(x: anytype) ?@TypeOf(x) {
return x;
}
fn print_my_guy(maybe_maybe_x: ??u32) void {
if(maybe_maybe_x) |maybe_x| {
if (maybe_x) |x| {
std.debug.print("that's Some(Some({d})) {any}\n", .{x, maybe_maybe_x});
} else {
std.debug.print("that's Some(None) {any}\n", .{maybe_maybe_x});
}
} else {
std.debug.print("that's None {any}\n", .{maybe_maybe_x});
}
}
pub fn main() void {
const a: ??u32 = 5;
const b: ??u32 = null;
const c: ??u32 = some(@as(?u32, null));
print_my_guy(a);
print_my_guy(b);
print_my_guy(c);
}