writeable 0.6.4

// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).

use std::fmt;
use writeable::assert_writeable_eq;
use writeable::LengthHint;
use writeable::Writeable;

/// A sample type implementing Writeable
struct WriteableMessage<'s> {
    message: &'s str,
}

impl Writeable for WriteableMessage<'_> {
    fn write_to<W: fmt::Write + ?Sized>(&self, sink: &mut W) -> fmt::Result {
        sink.write_str(self.message)
    }

    fn writeable_length_hint(&self) -> LengthHint {
        LengthHint::exact(self.message.len())
    }
}

writeable::impl_display_with_writeable!(WriteableMessage<'_>);

#[test]
fn test_basic() {
    let input_string = "hello world";
    let message = WriteableMessage {
        message: input_string,
    };
    assert_writeable_eq!(&message, input_string);
}

struct DelegatedMessage<'s>(WriteableMessage<'s>);

writeable::impl_writeable_delegate!(DelegatedMessage<'_>, |&self| &self.0);
writeable::impl_display_with_writeable!(DelegatedMessage<'_>);

#[test]
fn test_delegated() {
    let input_string = "hello world 2";
    let message = DelegatedMessage(WriteableMessage {
        message: input_string,
    });
    assert_writeable_eq!(&message, input_string);
}