rust/tests/ui/fn_to_numeric_cast_any.rs
2023-08-22 17:18:11 +02:00

95 lines
2.5 KiB
Rust

#![warn(clippy::fn_to_numeric_cast_any)]
#![allow(clippy::fn_to_numeric_cast, clippy::fn_to_numeric_cast_with_truncation)]
//@no-rustfix
fn foo() -> u8 {
0
}
fn generic_foo<T>(x: T) -> T {
x
}
trait Trait {
fn static_method() -> u32 {
2
}
}
struct Struct;
impl Trait for Struct {}
fn fn_pointer_to_integer() {
let _ = foo as i8;
//~^ ERROR: casting function pointer `foo` to `i8`
//~| NOTE: `-D clippy::fn-to-numeric-cast-any` implied by `-D warnings`
let _ = foo as i16;
//~^ ERROR: casting function pointer `foo` to `i16`
let _ = foo as i32;
//~^ ERROR: casting function pointer `foo` to `i32`
let _ = foo as i64;
//~^ ERROR: casting function pointer `foo` to `i64`
let _ = foo as i128;
//~^ ERROR: casting function pointer `foo` to `i128`
let _ = foo as isize;
//~^ ERROR: casting function pointer `foo` to `isize`
let _ = foo as u8;
//~^ ERROR: casting function pointer `foo` to `u8`
let _ = foo as u16;
//~^ ERROR: casting function pointer `foo` to `u16`
let _ = foo as u32;
//~^ ERROR: casting function pointer `foo` to `u32`
let _ = foo as u64;
//~^ ERROR: casting function pointer `foo` to `u64`
let _ = foo as u128;
//~^ ERROR: casting function pointer `foo` to `u128`
let _ = foo as usize;
//~^ ERROR: casting function pointer `foo` to `usize`
}
fn static_method_to_integer() {
let _ = Struct::static_method as usize;
//~^ ERROR: casting function pointer `Struct::static_method` to `usize`
}
fn fn_with_fn_arg(f: fn(i32) -> u32) -> usize {
f as usize
//~^ ERROR: casting function pointer `f` to `usize`
}
fn fn_with_generic_static_trait_method<T: Trait>() -> usize {
T::static_method as usize
//~^ ERROR: casting function pointer `T::static_method` to `usize`
}
fn closure_to_fn_to_integer() {
let clos = |x| x * 2_u32;
let _ = (clos as fn(u32) -> u32) as usize;
//~^ ERROR: casting function pointer `(clos as fn(u32) -> u32)` to `usize`
}
fn fn_to_raw_ptr() {
let _ = foo as *const ();
//~^ ERROR: casting function pointer `foo` to `*const ()`
}
fn cast_fn_to_self() {
// Casting to the same function pointer type should be permitted.
let _ = foo as fn() -> u8;
}
fn cast_generic_to_concrete() {
// Casting to a more concrete function pointer type should be permitted.
let _ = generic_foo as fn(usize) -> usize;
}
fn cast_closure_to_fn() {
// Casting a closure to a function pointer should be permitted.
let id = |x| x;
let _ = id as fn(usize) -> usize;
}
fn main() {}