rust/tests/ui/cast/cast-as-bool.rs
2023-09-18 14:03:57 +00:00

50 lines
1.7 KiB
Rust

fn main() {
let u = 5 as bool; //~ ERROR cannot cast `i32` as `bool`
//~| HELP compare with zero instead
//~| SUGGESTION != 0
let t = (1 + 2) as bool; //~ ERROR cannot cast `i32` as `bool`
//~| HELP compare with zero instead
//~| SUGGESTION != 0
let _ = 5_u32 as bool; //~ ERROR cannot cast `u32` as `bool`
//~| HELP compare with zero instead
let _ = 64.0_f64 as bool; //~ ERROR cannot cast `f64` as `bool`
//~| HELP compare with zero instead
// Enums that can normally be cast to integers can't be cast to `bool`, just like integers.
// Note that enums that cannot be cast to integers can't be cast to anything at *all*
// so that's not tested here.
enum IntEnum {
Zero,
One,
Two
}
let _ = IntEnum::One as bool; //~ ERROR cannot cast `IntEnum` as `bool`
fn uwu(_: u8) -> String {
todo!()
}
unsafe fn owo() {}
// fn item to bool
let _ = uwu as bool; //~ ERROR cannot cast `fn(u8) -> String {uwu}` as `bool`
// unsafe fn item
let _ = owo as bool; //~ ERROR cannot cast `unsafe fn() {owo}` as `bool`
// fn ptr to bool
let _ = uwu as fn(u8) -> String as bool; //~ ERROR cannot cast `fn(u8) -> String` as `bool`
let _ = 'x' as bool; //~ ERROR cannot cast `char` as `bool`
let ptr = 1 as *const ();
let _ = ptr as bool; //~ ERROR cannot cast `*const ()` as `bool`
let v = "hello" as bool;
//~^ ERROR casting `&'static str` as `bool` is invalid
//~| HELP consider using the `is_empty` method on `&'static str` to determine if it contains anything
}