pub const EnvNameHashContext = struct {
    fn upcase(c: u21) u21 {
        if (c <= std.math.maxInt(u16))
            return windows.ntdll.RtlUpcaseUnicodeChar(@as(u16, @intCast(c)));
        return c;
    }

    pub fn hash(self: @This(), s: []const u8) u64 {
        _ = self;
        if (native_os == .windows) {
            var h = std.hash.Wyhash.init(0);
            var it = unicode.Wtf8View.initUnchecked(s).iterator();
            while (it.nextCodepoint()) |cp| {
                const cp_upper = upcase(cp);
                h.update(&[_]u8{
                    @as(u8, @intCast((cp_upper >> 16) & 0xff)),
                    @as(u8, @intCast((cp_upper >> 8) & 0xff)),
                    @as(u8, @intCast((cp_upper >> 0) & 0xff)),
                });
            }
            return h.final();
        }
        return std.hash_map.hashString(s);
    }

    pub fn eql(self: @This(), a: []const u8, b: []const u8) bool {
        _ = self;
        if (native_os == .windows) {
            var it_a = unicode.Wtf8View.initUnchecked(a).iterator();
            var it_b = unicode.Wtf8View.initUnchecked(b).iterator();
            while (true) {
                const c_a = it_a.nextCodepoint() orelse break;
                const c_b = it_b.nextCodepoint() orelse return false;
                if (upcase(c_a) != upcase(c_b))
                    return false;
            }
            return if (it_b.nextCodepoint()) |_| false else true;
        }
        return std.hash_map.eqlString(a, b);
    }
}