diff --git a/src/test/ui/array-slice-vec/subslice-patterns-pass.rs b/src/test/ui/array-slice-vec/subslice-patterns-pass.rs new file mode 100644 index 0000000000000..1ebf3def78876 --- /dev/null +++ b/src/test/ui/array-slice-vec/subslice-patterns-pass.rs @@ -0,0 +1,128 @@ +// This test comprehensively checks the passing static and dynamic semantics +// of subslice patterns `..`, `x @ ..`, `ref x @ ..`, and `ref mut @ ..` +// in slice patterns `[$($pat), $(,)?]` . + +// run-pass + +#![feature(slice_patterns)] + +#![allow(unreachable_patterns)] + +use std::convert::identity; + +#[derive(PartialEq, Debug, Clone)] +struct N(u8); + +macro_rules! n { + ($($e:expr),* $(,)?) => { + [$(N($e)),*] + } +} + +macro_rules! c { + ($inp:expr, $typ:ty, $out:expr $(,)?) => { + assert_eq!($out, identity::<$typ>($inp)); + } +} + +macro_rules! m { + ($e:expr, $p:pat => $b:expr) => { + match $e { + $p => $b, + _ => panic!(), + } + } +} + +fn main() { + slices(); + arrays(); +} + +fn slices() { + // Matching slices using `ref` patterns: + let mut v = vec![N(0), N(1), N(2), N(3), N(4)]; + let mut vc = (0..=4).collect::>(); + + let [..] = v[..]; // Always matches. + m!(v[..], [N(0), ref sub @ .., N(4)] => c!(sub, &[N], n![1, 2, 3])); + m!(v[..], [N(0), ref sub @ ..] => c!(sub, &[N], n![1, 2, 3, 4])); + m!(v[..], [ref sub @ .., N(4)] => c!(sub, &[N], n![0, 1, 2, 3])); + m!(v[..], [ref sub @ .., _, _, _, _, _] => c!(sub, &[N], &n![] as &[N])); + m!(v[..], [_, _, _, _, _, ref sub @ ..] => c!(sub, &[N], &n![] as &[N])); + m!(vc[..], [x, .., y] => c!((x, y), (u8, u8), (0, 4))); + + // Matching slices using `ref mut` patterns: + let [..] = v[..]; // Always matches. + m!(v[..], [N(0), ref mut sub @ .., N(4)] => c!(sub, &mut [N], n![1, 2, 3])); + m!(v[..], [N(0), ref mut sub @ ..] => c!(sub, &mut [N], n![1, 2, 3, 4])); + m!(v[..], [ref mut sub @ .., N(4)] => c!(sub, &mut [N], n![0, 1, 2, 3])); + m!(v[..], [ref mut sub @ .., _, _, _, _, _] => c!(sub, &mut [N], &mut n![] as &mut [N])); + m!(v[..], [_, _, _, _, _, ref mut sub @ ..] => c!(sub, &mut [N], &mut n![] as &mut [N])); + m!(vc[..], [x, .., y] => c!((x, y), (u8, u8), (0, 4))); + + // Matching slices using default binding modes (&): + let [..] = &v[..]; // Always matches. + m!(&v[..], [N(0), sub @ .., N(4)] => c!(sub, &[N], n![1, 2, 3])); + m!(&v[..], [N(0), sub @ ..] => c!(sub, &[N], n![1, 2, 3, 4])); + m!(&v[..], [sub @ .., N(4)] => c!(sub, &[N], n![0, 1, 2, 3])); + m!(&v[..], [sub @ .., _, _, _, _, _] => c!(sub, &[N], &n![] as &[N])); + m!(&v[..], [_, _, _, _, _, sub @ ..] => c!(sub, &[N], &n![] as &[N])); + m!(&vc[..], [x, .., y] => c!((x, y), (&u8, &u8), (&0, &4))); + + // Matching slices using default binding modes (&mut): + let [..] = &mut v[..]; // Always matches. + m!(&mut v[..], [N(0), sub @ .., N(4)] => c!(sub, &mut [N], n![1, 2, 3])); + m!(&mut v[..], [N(0), sub @ ..] => c!(sub, &mut [N], n![1, 2, 3, 4])); + m!(&mut v[..], [sub @ .., N(4)] => c!(sub, &mut [N], n![0, 1, 2, 3])); + m!(&mut v[..], [sub @ .., _, _, _, _, _] => c!(sub, &mut [N], &mut n![] as &mut [N])); + m!(&mut v[..], [_, _, _, _, _, sub @ ..] => c!(sub, &mut [N], &mut n![] as &mut [N])); + m!(&mut vc[..], [x, .., y] => c!((x, y), (&mut u8, &mut u8), (&mut 0, &mut 4))); +} + +fn arrays() { + let mut v = n![0, 1, 2, 3, 4]; + let vc = [0, 1, 2, 3, 4]; + + // Matching arrays by value: + m!(v.clone(), [N(0), sub @ .., N(4)] => c!(sub, [N; 3], n![1, 2, 3])); + m!(v.clone(), [N(0), sub @ ..] => c!(sub, [N; 4], n![1, 2, 3, 4])); + m!(v.clone(), [sub @ .., N(4)] => c!(sub, [N; 4], n![0, 1, 2, 3])); + m!(v.clone(), [sub @ .., _, _, _, _, _] => c!(sub, [N; 0], n![] as [N; 0])); + m!(v.clone(), [_, _, _, _, _, sub @ ..] => c!(sub, [N; 0], n![] as [N; 0])); + m!(v.clone(), [x, .., y] => c!((x, y), (N, N), (N(0), N(4)))); + m!(v.clone(), [..] => ()); + + // Matching arrays by ref patterns: + m!(v, [N(0), ref sub @ .., N(4)] => c!(sub, &[N; 3], &n![1, 2, 3])); + m!(v, [N(0), ref sub @ ..] => c!(sub, &[N; 4], &n![1, 2, 3, 4])); + m!(v, [ref sub @ .., N(4)] => c!(sub, &[N; 4], &n![0, 1, 2, 3])); + m!(v, [ref sub @ .., _, _, _, _, _] => c!(sub, &[N; 0], &n![] as &[N; 0])); + m!(v, [_, _, _, _, _, ref sub @ ..] => c!(sub, &[N; 0], &n![] as &[N; 0])); + m!(vc, [x, .., y] => c!((x, y), (u8, u8), (0, 4))); + + // Matching arrays by ref mut patterns: + m!(v, [N(0), ref mut sub @ .., N(4)] => c!(sub, &mut [N; 3], &mut n![1, 2, 3])); + m!(v, [N(0), ref mut sub @ ..] => c!(sub, &mut [N; 4], &mut n![1, 2, 3, 4])); + m!(v, [ref mut sub @ .., N(4)] => c!(sub, &mut [N; 4], &mut n![0, 1, 2, 3])); + m!(v, [ref mut sub @ .., _, _, _, _, _] => c!(sub, &mut [N; 0], &mut n![] as &mut [N; 0])); + m!(v, [_, _, _, _, _, ref mut sub @ ..] => c!(sub, &mut [N; 0], &mut n![] as &mut [N; 0])); + + // Matching arrays by default binding modes (&): + m!(&v, [N(0), sub @ .., N(4)] => c!(sub, &[N; 3], &n![1, 2, 3])); + m!(&v, [N(0), sub @ ..] => c!(sub, &[N; 4], &n![1, 2, 3, 4])); + m!(&v, [sub @ .., N(4)] => c!(sub, &[N; 4], &n![0, 1, 2, 3])); + m!(&v, [sub @ .., _, _, _, _, _] => c!(sub, &[N; 0], &n![] as &[N; 0])); + m!(&v, [_, _, _, _, _, sub @ ..] => c!(sub, &[N; 0], &n![] as &[N; 0])); + m!(&v, [..] => ()); + m!(&v, [x, .., y] => c!((x, y), (&N, &N), (&N(0), &N(4)))); + + // Matching arrays by default binding modes (&mut): + m!(&mut v, [N(0), sub @ .., N(4)] => c!(sub, &mut [N; 3], &mut n![1, 2, 3])); + m!(&mut v, [N(0), sub @ ..] => c!(sub, &mut [N; 4], &mut n![1, 2, 3, 4])); + m!(&mut v, [sub @ .., N(4)] => c!(sub, &mut [N; 4], &mut n![0, 1, 2, 3])); + m!(&mut v, [sub @ .., _, _, _, _, _] => c!(sub, &mut [N; 0], &mut n![] as &[N; 0])); + m!(&mut v, [_, _, _, _, _, sub @ ..] => c!(sub, &mut [N; 0], &mut n![] as &[N; 0])); + m!(&mut v, [..] => ()); + m!(&mut v, [x, .., y] => c!((x, y), (&mut N, &mut N), (&mut N(0), &mut N(4)))); +}