From 64d98f8ee037282c35007b64c2649055c56af1db Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Wed, 17 Apr 2024 14:19:03 +0200 Subject: Merging upstream version 1.68.2+dfsg1. Signed-off-by: Daniel Baumann --- ...opagate-fail-to-approximate-longer-no-bounds.rs | 42 ++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 tests/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.rs (limited to 'tests/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.rs') diff --git a/tests/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.rs b/tests/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.rs new file mode 100644 index 000000000..dcd05d7fa --- /dev/null +++ b/tests/ui/nll/closure-requirements/propagate-fail-to-approximate-longer-no-bounds.rs @@ -0,0 +1,42 @@ +// Similarly to escape-argument-callee, a test case where the closure +// requires a relationship between 2 unrelated higher-ranked regions, +// with no helpful relations between the HRRs and free regions. +// +// In this case, the error is reported by the closure itself. This is +// because it is unable to approximate the higher-ranked region `'x`, +// as it knows of no relationships between `'x` and any +// non-higher-ranked regions. + +// compile-flags:-Zverbose + +#![feature(rustc_attrs)] + +use std::cell::Cell; + +// Callee knows that: +// +// 'b: 'y +// +// but this doesn't really help us in proving that `'x: 'y`, so closure gets an error. +fn establish_relationships<'a, 'b, F>(_cell_a: &Cell<&'a u32>, _cell_b: &Cell<&'b u32>, _closure: F) +where + F: for<'x, 'y> FnMut( + &Cell<&'y &'b u32>, // shows that 'b: 'y + &Cell<&'x u32>, + &Cell<&'y u32>, + ), +{ +} + +fn demand_y<'x, 'y>(_cell_x: &Cell<&'x u32>, _cell_y: &Cell<&'y u32>, _y: &'y u32) {} + +#[rustc_regions] +fn supply<'a, 'b>(cell_a: Cell<&'a u32>, cell_b: Cell<&'b u32>) { + establish_relationships(&cell_a, &cell_b, |_outlives, x, y| { + // Only works if 'x: 'y: + demand_y(x, y, x.get()) + //~^ ERROR + }); +} + +fn main() {} -- cgit v1.2.3