[rustc.git] / src / tools / clippy / tests / ui / cast_ref_to_mut.rs

#![warn(clippy::cast_ref_to_mut)]
#![allow(clippy::no_effect)]

extern "C" {
    // N.B., mutability can be easily incorrect in FFI calls -- as
    // in C, the default is mutable pointers.
    fn ffi(c: *mut u8);
    fn int_ffi(c: *mut i32);
}

fn main() {
    let s = String::from("Hello");
    let a = &s;
    unsafe {
        let num = &3i32;
        let mut_num = &mut 3i32;
        // Should be warned against
        (*(a as *const _ as *mut String)).push_str(" world");
        *(a as *const _ as *mut _) = String::from("Replaced");
        *(a as *const _ as *mut String) += " world";
        // Shouldn't be warned against
        println!("{}", *(num as *const _ as *const i16));
        println!("{}", *(mut_num as *mut _ as *mut i16));
        ffi(a.as_ptr() as *mut _);
        int_ffi(num as *const _ as *mut _);
        int_ffi(&3 as *const _ as *mut _);
        let mut value = 3;
        let value: *const i32 = &mut value;
        *(value as *const i16 as *mut i16) = 42;
    }
}
Commit	Line	Data
f20569fa XL	1	#![warn(clippy::cast_ref_to_mut)]
	2	#![allow(clippy::no_effect)]
	3
	4	extern "C" {
	5	// N.B., mutability can be easily incorrect in FFI calls -- as
	6	// in C, the default is mutable pointers.
	7	fn ffi(c: *mut u8);
	8	fn int_ffi(c: *mut i32);
	9	}
	10
	11	fn main() {
	12	let s = String::from("Hello");
	13	let a = &s;
	14	unsafe {
	15	let num = &3i32;
	16	let mut_num = &mut 3i32;
	17	// Should be warned against
	18	((a as const _ as *mut String)).push_str(" world");
	19	(a as const _ as *mut _) = String::from("Replaced");
	20	(a as const _ as *mut String) += " world";
	21	// Shouldn't be warned against
	22	println!("{}", (num as const _ as *const i16));
	23	println!("{}", (mut_num as mut _ as *mut i16));
	24	ffi(a.as_ptr() as *mut _);
	25	int_ffi(num as const _ as mut _);
	26	int_ffi(&3 as const _ as mut _);
	27	let mut value = 3;
	28	let value: *const i32 = &mut value;
	29	(value as const i16 as *mut i16) = 42;
	30	}
	31	}