9153d8ad6c
parameters This involves numerous substeps: 1. Treat Self same as any other parameter. 2. No longer compute offsets for method parameters. 3. Store all generic types (both trait/impl and method) with a method, eliminating odd discrepancies. 4. Stop doing unspeakable things to static methods and instead just use the natural types, now that we can easily add the type parameters from trait into the method's polytype. 5. No doubt some more. It was hard to separate these into distinct commits. Fixes #13564
74 lines
2.0 KiB
Rust
74 lines
2.0 KiB
Rust
// Copyright 2012 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 we correctly infer variance for region parameters in
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// various self-contained types.
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// Regions that just appear in normal spots are contravariant:
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#[rustc_variance]
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struct Test2<'a, 'b, 'c> { //~ ERROR regions=[[-, -, -];[];[]]
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x: &'a int,
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y: &'b [int],
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c: &'c str
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}
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// Those same annotations in function arguments become covariant:
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#[rustc_variance]
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struct Test3<'a, 'b, 'c> { //~ ERROR regions=[[+, +, +];[];[]]
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x: extern "Rust" fn(&'a int),
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y: extern "Rust" fn(&'b [int]),
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c: extern "Rust" fn(&'c str),
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}
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// Mutability induces invariance:
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#[rustc_variance]
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struct Test4<'a, 'b> { //~ ERROR regions=[[-, o];[];[]]
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x: &'a mut &'b int,
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}
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// Mutability induces invariance, even when in a
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// contravariant context:
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#[rustc_variance]
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struct Test5<'a, 'b> { //~ ERROR regions=[[+, o];[];[]]
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x: extern "Rust" fn(&'a mut &'b int),
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}
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// Invariance is a trap from which NO ONE CAN ESCAPE.
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// In other words, even though the `&'b int` occurs in
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// a argument list (which is contravariant), that
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// argument list occurs in an invariant context.
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#[rustc_variance]
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struct Test6<'a, 'b> { //~ ERROR regions=[[-, o];[];[]]
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x: &'a mut extern "Rust" fn(&'b int),
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}
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// No uses at all is bivariant:
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#[rustc_variance]
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struct Test7<'a> { //~ ERROR regions=[[*];[];[]]
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x: int
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}
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// Try enums too.
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#[rustc_variance]
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enum Test8<'a, 'b, 'c> { //~ ERROR regions=[[+, -, o];[];[]]
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Test8A(extern "Rust" fn(&'a int)),
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Test8B(&'b [int]),
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Test8C(&'b mut &'c str),
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}
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fn main() {}
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