b60de4bfc2
This is not technically a [breaking-change], but it will be soon, so
you should update your code. Typically, shadowing is accidental, and
the shadowing lifetime can simply be removed. This frequently occurs
in constructor patterns:
```rust
// Old:
impl<'a> SomeStruct<'a> { fn new<'a>(..) -> SomeStruct<'a> { ... } }
// Should be:
impl<'a> SomeStruct<'a> { fn new(..) -> SomeStruct<'a> { ... } }
```
Otherwise, you should rename the inner lifetime to something
else. Note though that lifetime elision frequently applies:
```rust
// Old
impl<'a> SomeStruct<'a> {
fn get<'a>(x: &'a self) -> &'a T { &self.field }
}
// Should be:
impl<'a> SomeStruct<'a> {
fn get(x: &self) -> &T { &self.field }
}
``
44 lines
1.5 KiB
Rust
44 lines
1.5 KiB
Rust
// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// Test that shadowed lifetimes generate an error.
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struct Foo<'a>(&'a int);
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impl<'a> Foo<'a> {
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//~^ HELP shadowed lifetime `'a` declared here
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fn shadow_in_method<'a>(&'a self) -> &'a int {
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//~^ WARNING lifetime name `'a` shadows another lifetime name that is already in scope
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//~| HELP deprecated
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self.0
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}
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fn shadow_in_type<'b>(&'b self) -> &'b int {
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//~^ HELP shadowed lifetime `'b` declared here
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let x: for<'b> fn(&'b int) = panic!();
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//~^ WARNING lifetime name `'b` shadows another lifetime name that is already in scope
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//~| HELP deprecated
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self.0
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}
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fn not_shadow_in_item<'b>(&'b self) {
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struct Bar<'a, 'b>(&'a int, &'b int); // not a shadow, separate item
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fn foo<'a, 'b>(x: &'a int, y: &'b int) { } // same
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}
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}
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fn main() {
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// intentional error that occurs after `resolve_lifetime` runs,
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// just to ensure that this test fails to compile; when shadowed
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// lifetimes become either an error or a proper lint, this will
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// not be needed.
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let x: int = 3u; //~ ERROR mismatched types
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}
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