rust/tests/ui/infallible_destructuring_match.rs
2018-10-06 09:43:08 -07:00

96 lines
2.0 KiB
Rust

// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![feature(tool_lints)]
#![feature(exhaustive_patterns, never_type)]
#![allow(clippy::let_and_return)]
enum SingleVariantEnum {
Variant(i32),
}
struct TupleStruct(i32);
enum EmptyEnum {}
fn infallible_destructuring_match_enum() {
let wrapper = SingleVariantEnum::Variant(0);
// This should lint!
let data = match wrapper {
SingleVariantEnum::Variant(i) => i,
};
// This shouldn't!
let data = match wrapper {
SingleVariantEnum::Variant(_) => -1,
};
// Neither should this!
let data = match wrapper {
SingleVariantEnum::Variant(i) => -1,
};
let SingleVariantEnum::Variant(data) = wrapper;
}
fn infallible_destructuring_match_struct() {
let wrapper = TupleStruct(0);
// This should lint!
let data = match wrapper {
TupleStruct(i) => i,
};
// This shouldn't!
let data = match wrapper {
TupleStruct(_) => -1,
};
// Neither should this!
let data = match wrapper {
TupleStruct(i) => -1,
};
let TupleStruct(data) = wrapper;
}
fn never_enum() {
let wrapper: Result<i32, !> = Ok(23);
// This should lint!
let data = match wrapper {
Ok(i) => i,
};
// This shouldn't!
let data = match wrapper {
Ok(_) => -1,
};
// Neither should this!
let data = match wrapper {
Ok(i) => -1,
};
let Ok(data) = wrapper;
}
impl EmptyEnum {
fn match_on(&self) -> ! {
// The lint shouldn't pick this up, as `let` won't work here!
let data = match *self {};
data
}
}
fn main() {}