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78 lines
2.1 KiB
Rust
78 lines
2.1 KiB
Rust
// Test that we are imposing the requirement that every associated
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// type of a bound that appears in the where clause on a struct must
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// outlive the location in which the type appears. Issue #22246.
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#![allow(dead_code)]
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#![feature(rustc_attrs)]
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pub trait TheTrait {
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type TheAssocType;
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}
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pub struct TheType<'b> {
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m: [fn(&'b()); 0]
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}
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impl<'b> TheTrait for TheType<'b> {
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type TheAssocType = &'b ();
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}
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pub struct WithAssoc<T:TheTrait> {
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m: [T; 0]
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}
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pub struct WithoutAssoc<T> {
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m: [T; 0]
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}
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fn with_assoc<'a,'b>() {
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// For this type to be valid, the rules require that all
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// associated types of traits that appear in `WithAssoc` must
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// outlive 'a. In this case, that means TheType<'b>::TheAssocType,
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// which is &'b (), must outlive 'a.
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// FIXME (#54943) NLL doesn't enforce WF condition in unreachable code if
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// `_x` is changed to `_`
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let _x: &'a WithAssoc<TheType<'b>> = loop { };
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//~^ ERROR lifetime may not live long enough
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}
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fn with_assoc1<'a,'b>() where 'b : 'a {
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// For this type to be valid, the rules require that all
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// associated types of traits that appear in `WithAssoc` must
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// outlive 'a. In this case, that means TheType<'b>::TheAssocType,
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// which is &'b (), must outlive 'a, so 'b : 'a must hold, and
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// that is in the where clauses, so we're fine.
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let _x: &'a WithAssoc<TheType<'b>> = loop { };
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}
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fn without_assoc<'a,'b>() {
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// Here there are no associated types but there is a requirement
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// that `'b:'a` holds because the `'b` appears in `TheType<'b>`.
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let _x: &'a WithoutAssoc<TheType<'b>> = loop { };
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//~^ ERROR lifetime may not live long enough
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}
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fn call_with_assoc<'a,'b>() {
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// As `with_assoc`, but just checking that we impose the same rule
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// on the value supplied for the type argument, even when there is
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// no data.
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call::<&'a WithAssoc<TheType<'b>>>();
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//~^ ERROR lifetime may not live long enough
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}
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fn call_without_assoc<'a,'b>() {
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// As `without_assoc`, but in a distinct scenario.
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call::<&'a WithoutAssoc<TheType<'b>>>();
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//~^ ERROR lifetime may not live long enough
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}
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fn call<T>() { }
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fn main() {
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}
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