const std = #import("std");
const print = std.print;
const exit = std.os.exit;
const byte_equal = std.byte_equal;

const foo = fn (string: []const u8, wanted: []const u8) ?[]const u8 {
    if (byte_equal(string, wanted)) {
        return string;
    } else {
        return null;
    }
}

const main = fn () *!void {
    const original: []const u8 = "fasdasD";
    var f = original;
    f = "foooo";

    if (foo(f, original)) |string| {
        print("string: ");
        print(string);
        print("\n");
        exit(1);
    } else {
    }
}