dizzy 0.2.0

Macros for safely interacting with DST newtypes
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33

use std::borrow::Cow;
use std::marker::PhantomData;

use dizzy::DstNewtype;

/// A wrapper around `str` with no extra semantics. This type exists to test how `dizzy` deals with
/// complex generic parameters.
#[derive(DstNewtype)]
#[dizzy(invariant = dizzy::trivial, error = std::convert::Infallible)]
#[dizzy(constructor = const new)]
#[dizzy(owned = StrBuf(String))]
#[dizzy(derive(Debug))]
#[dizzy(derive_owned(Debug))]
#[repr(transparent)]
struct Str<'a, 'b, T, U = ()> {
    __data: PhantomData<(T, U, &'a (), &'b ())>,
    inner: str,
}

#[test]
fn cow_from_owned() {
    let s: &Str<'_, '_, ()> = Str::new("hello").unwrap();
    let buf: StrBuf<'_, '_, ()> = s.to_owned();
    let cow: Cow<'_, Str<'_, '_, ()>> = Cow::from(&buf);
    assert!(matches!(cow, Cow::Owned(_)));
}

#[test]
fn debug_impls_are_equivalent() {
    let s: &Str<'_, '_, ()> = Str::new("hello").unwrap();
    let buf: StrBuf<'_, '_, ()> = s.to_owned();
    assert_eq!(format!("{s:?}"), format!("{buf:?}"));
}