rust/tests/ui/nll/closure-requirements/escape-argument.rs
2023-01-11 09:32:08 +00:00

43 lines
926 B
Rust

// Test closure that:
//
// - takes an argument `y`
// - stores `y` into another, longer-lived spot
//
// but is invoked with a spot that doesn't live long
// enough to store `y`.
//
// The error is reported in the caller: invoking the closure links the
// lifetime of the variable that is given as `y` (via subtyping) and
// thus forces the corresponding borrow to live too long. This is
// basically checking that the MIR type checker correctly enforces the
// closure signature.
// compile-flags:-Zverbose
#![feature(rustc_attrs)]
#[rustc_regions]
fn test() {
let x = 44;
let mut p = &x;
{
let y = 22;
let mut closure = expect_sig(|p, y| *p = y);
closure(&mut p, &y);
//~^ ERROR `y` does not live long enough [E0597]
}
deref(p);
}
fn expect_sig<F>(f: F) -> F
where F: for<'a, 'b> FnMut(&'a mut &'b i32, &'b i32)
{
f
}
fn deref(_p: &i32) { }
fn main() { }