59 lines
1.8 KiB
Rust
59 lines
1.8 KiB
Rust
// edition:2018
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// Check that lifetime resolver enforces the lifetime name scoping
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// rules correctly in various scenarios.
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struct Foo<'a> {
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x: &'a isize
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}
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impl<'a> Foo<'a> {
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// &'a is inherited:
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fn m1(&self, arg: &'a isize) { }
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fn m2(&'a self) { }
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fn m3(&self, arg: Foo<'a>) { }
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// &'b is not:
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fn m4(&self, arg: &'b isize) { } //~ ERROR undeclared lifetime
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fn m5(&'b self) { } //~ ERROR undeclared lifetime
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fn m6(&self, arg: Foo<'b>) { } //~ ERROR undeclared lifetime
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}
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fn bar<'a>(x: &'a isize) {
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// &'a is visible to code:
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let y: &'a isize = x;
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// &'a is not visible to *items*:
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type X = Option<&'a isize>; //~ ERROR can't use generic parameters from outer item
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enum E {
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E1(&'a isize) //~ ERROR can't use generic parameters from outer item
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}
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struct S {
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f: &'a isize //~ ERROR can't use generic parameters from outer item
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}
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fn f(a: &'a isize) { } //~ ERROR can't use generic parameters from outer item
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// &'a CAN be declared on functions and used then:
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fn g<'a>(a: &'a isize) { } // OK
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fn h(a: Box<dyn for<'a> FnOnce(&'a isize)>) { } // OK
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}
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// Test nesting of lifetimes in fn type declarations
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fn fn_types(a: &'a isize, //~ ERROR undeclared lifetime
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b: Box<dyn for<'a> FnOnce(&'a isize,
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&'b isize, //~ ERROR undeclared lifetime
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Box<dyn for<'b> FnOnce(&'a isize,
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&'b isize)>,
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&'b isize)>, //~ ERROR undeclared lifetime
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c: &'a isize) //~ ERROR undeclared lifetime
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{
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}
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struct Bug {}
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impl Bug {
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async fn buggy(&self) -> &'a str { //~ ERROR use of undeclared lifetime name `'a`
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todo!()
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}
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}
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pub fn main() {}
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