rust/tests/ui/cleanup-rvalue-for-scope.rs
2023-01-11 09:32:08 +00:00

64 lines
1.1 KiB
Rust

// run-pass
#![allow(non_snake_case)]
#![allow(dead_code)]
#![allow(unused_variables)]
// Test that the lifetime of rvalues in for loops is extended
// to the for loop itself.
use std::ops::Drop;
static mut FLAGS: u64 = 0;
struct Box<T> { f: T }
struct AddFlags { bits: u64 }
fn AddFlags(bits: u64) -> AddFlags {
AddFlags { bits: bits }
}
fn arg(exp: u64, _x: &AddFlags) {
check_flags(exp);
}
fn pass<T>(v: T) -> T {
v
}
fn check_flags(exp: u64) {
unsafe {
let x = FLAGS;
FLAGS = 0;
println!("flags {}, expected {}", x, exp);
assert_eq!(x, exp);
}
}
impl AddFlags {
fn check_flags(&self, exp: u64) -> &AddFlags {
check_flags(exp);
self
}
fn bits(&self) -> u64 {
self.bits
}
}
impl Drop for AddFlags {
fn drop(&mut self) {
unsafe {
FLAGS = FLAGS + self.bits;
}
}
}
pub fn main() {
// The array containing [AddFlags] should not be dropped until
// after the for loop:
for x in &[AddFlags(1)] {
check_flags(0);
}
check_flags(1);
}