rust/tests/ui/parser/mut-patterns.rs

49 lines
1.6 KiB
Rust

// Can't put mut in non-ident pattern
//@ edition:2018
#![feature(box_patterns)]
#![allow(warnings)]
pub fn main() {
let mut _ = 0; //~ ERROR `mut` must be followed by a named binding
let mut (_, _) = (0, 0); //~ ERROR `mut` must be followed by a named binding
let mut (x @ y) = 0; //~ ERROR `mut` must be attached to each individual binding
let mut mut x = 0;
//~^ ERROR `mut` on a binding may not be repeated
//~| remove the additional `mut`s
struct Foo { x: isize }
let mut Foo { x: x } = Foo { x: 3 };
//~^ ERROR `mut` must be attached to each individual binding
//~| add `mut` to each binding
let mut Foo { x } = Foo { x: 3 };
//~^ ERROR `mut` must be attached to each individual binding
//~| add `mut` to each binding
struct r#yield(u8, u8);
let mut mut yield(become, await) = r#yield(0, 0);
//~^ ERROR `mut` on a binding may not be repeated
//~| ERROR `mut` must be followed by a named binding
//~| ERROR expected identifier, found reserved keyword `yield`
//~| ERROR expected identifier, found reserved keyword `become`
//~| ERROR expected identifier, found keyword `await`
struct W<T, U>(T, U);
struct B { f: Box<u8> }
let mut W(mut a, W(b, W(ref c, W(d, B { box f }))))
//~^ ERROR `mut` must be attached to each individual binding
= W(0, W(1, W(2, W(3, B { f: Box::new(4u8) }))));
// Make sure we don't accidentally allow `mut $p` where `$p:pat`.
macro_rules! foo {
($p:pat) => {
let mut $p = 0; //~ ERROR expected identifier, found `x`
}
}
foo!(x);
}