56 lines
2.1 KiB
Rust
56 lines
2.1 KiB
Rust
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// Copyright 2014 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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// Check that explicit region bounds are allowed on the various
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// nominal types (but not on other types) and that they are type
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// checked.
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struct Inv<'a> { // invariant w/r/t 'a
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x: &'a mut &'a int
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}
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pub trait Foo<'a> {
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fn no_bound<'b>(self, b: Inv<'b>);
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fn has_bound<'b:'a>(self, b: Inv<'b>);
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fn wrong_bound1<'b,'c,'d:'a+'b>(self, b: Inv<'b>, c: Inv<'c>, d: Inv<'d>);
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fn wrong_bound2<'b,'c,'d:'a+'b+'c>(self, b: Inv<'b>, c: Inv<'c>, d: Inv<'d>);
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}
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impl<'a> Foo<'a> for &'a int {
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fn no_bound<'b:'a>(self, b: Inv<'b>) {
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//~^ ERROR lifetime parameters or bounds on method `no_bound` do not match
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}
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fn has_bound<'b>(self, b: Inv<'b>) {
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//~^ ERROR lifetime parameters or bounds on method `has_bound` do not match
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}
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fn wrong_bound1<'b,'c,'d:'a+'c>(self, b: Inv<'b>, c: Inv<'c>, d: Inv<'d>) {
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//~^ ERROR method `wrong_bound1` has an incompatible type for trait
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//
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// Note: This is a terrible error message. It is caused
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// because, in the trait, 'b is early bound, and in the impl,
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// 'c is early bound, so -- after substitution -- the
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// lifetimes themselves look isomorphic. We fail because the
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// lifetimes that appear in the types are in the wrong
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// order. This should really be fixed by keeping more
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// information about the lifetime declarations in the trait so
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// that we can compare better to the impl, even in cross-crate
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// cases.
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}
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fn wrong_bound2<'b,'c,'e:'b+'c>(self, b: Inv<'b>, c: Inv<'c>, e: Inv<'e>) {
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//~^ ERROR distinct set of bounds from its counterpart
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}
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}
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fn main() { }
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