rust/tests/ui/issues/issue-20055-box-unsized-array.rs

// run-pass
// Issue #2005: Check that boxed fixed-size arrays are properly
// accounted for (namely, only deallocated if they were actually
// created) when they appear as temporaries in unused arms of a match
// expression.

pub fn foo(box_1: fn () -> Box<[i8; 1]>,
           box_2: fn () -> Box<[i8; 20]>,
           box_3: fn () -> Box<[i8; 300]>,
           box_4: fn () -> Box<[i8; 4000]>,
            ) {
    println!("Hello World 1");
    let _: Box<[i8]> = match 3 {
        1 => box_1(),
        2 => box_2(),
        3 => box_3(),
        _ => box_4(),
    };
    println!("Hello World 2");
}

pub fn main() {
    fn box_1() -> Box<[i8; 1]> { Box::new( [1] ) }
    fn box_2() -> Box<[i8; 20]> { Box::new( [1; 20] ) }
    fn box_3() -> Box<[i8; 300]> { Box::new( [1; 300] ) }
    fn box_4() -> Box<[i8; 4000]> { Box::new( [1; 4000] ) }

    foo(box_1, box_2, box_3, box_4);
}