mirror of https://github.com/rust-lang/rust
75 lines
1.3 KiB
Rust
75 lines
1.3 KiB
Rust
// Test that we infer the expected type of a pattern to an array of the given length.
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#![allow(unused_variables)]
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use std::array::TryFromSliceError;
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use std::convert::TryInto;
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struct Zeroes;
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impl Into<[usize; 2]> for Zeroes {
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fn into(self) -> [usize; 2] {
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[0; 2]
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}
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}
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impl Into<[usize; 3]> for Zeroes {
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fn into(self) -> [usize; 3] {
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[0; 3]
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}
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}
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impl Into<[usize; 4]> for Zeroes {
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fn into(self) -> [usize; 4] {
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[0; 4]
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}
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}
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fn zeroes_into() {
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let [a, b, c] = Zeroes.into();
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let [d, e, f]: [_; 3] = Zeroes.into();
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}
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fn array_try_from(x: &[usize]) -> Result<usize, TryFromSliceError> {
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let [a, b] = x.try_into()?;
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Ok(a + b)
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}
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fn destructuring_assignment() {
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let a: i32;
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let b;
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[a, b] = Default::default();
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}
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fn test_nested_array() {
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let a: [_; 3];
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let b;
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//~^ ERROR type annotations needed
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[a, b] = Default::default();
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}
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fn test_nested_array_type_hint() {
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let a: [_; 3];
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let b;
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[a, b] = Default::default();
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let _: i32 = b[1];
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}
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fn test_working_nested_array() {
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let a: i32;
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[[a, _, _], _, _] = Default::default();
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}
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struct Foo<T>([T; 2]);
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impl<T: Default + Copy> Default for Foo<T> {
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fn default() -> Self {
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Foo([Default::default(); 2])
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}
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}
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fn field_array() {
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let a: i32;
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let b;
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Foo([a, b]) = Default::default();
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}
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fn main() {}
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