pub fn uvarint(buf: []u8) !u64 {
    var x: u64 = 0;
    var s: u64 = 0;

    for (buf) |i, b| {
        if (b < 0x80) {
            if (i > 9 or (i == 9 and b > 1)) {
                return error.Overflow;
            }
            return x | (u64)(b) << s;
        }
        x |= (u64)(b & 0x7f) << s;
        s += 7;
    }
    return error.BufferTooSmall;
}


test "varint" {

    var buf_data = []u8{1, 2, 3, 4};
    var buf = buf_data[0..];
    const x = uvarint(buf);

}


Output:


zig/std/varint.zig:12:36: error: expected type 'u6', found 'u64'
            return x | (u64)(b) << s;
                                   ^