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Diffstat (limited to '')
-rw-r--r-- | src/test/ui/nll/drop-may-dangle.rs | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/src/test/ui/nll/drop-may-dangle.rs b/src/test/ui/nll/drop-may-dangle.rs new file mode 100644 index 000000000..b5531c29b --- /dev/null +++ b/src/test/ui/nll/drop-may-dangle.rs @@ -0,0 +1,34 @@ +// Basic test for liveness constraints: the region (`R1`) that appears +// in the type of `p` includes the points after `&v[0]` up to (but not +// including) the call to `use_x`. The `else` branch is not included. + +// check-pass + +#![allow(warnings)] +#![feature(dropck_eyepatch)] + +fn use_x(_: usize) -> bool { true } + +fn main() { + let mut v = [1, 2, 3]; + let p: WrapMayDangle<& /* R4 */ usize> = WrapMayDangle { value: &v[0] }; + if true { + // `p` will get dropped at end of this block. However, because of + // the `#[may_dangle]` attribute, we do not need to consider R4 + // live after this point. + use_x(*p.value); + } else { + v[0] += 1; + use_x(22); + } + + v[0] += 1; +} + +struct WrapMayDangle<T> { + value: T +} + +unsafe impl<#[may_dangle] T> Drop for WrapMayDangle<T> { + fn drop(&mut self) { } +} |