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// check-fail
#![feature(ptr_from_ref)]
#![deny(invalid_reference_casting)]
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;
(*(a as *const _ as *mut String)).push_str(" world");
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
*(a as *const _ as *mut _) = String::from("Replaced");
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
*(a as *const _ as *mut String) += " world";
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
let _num = &mut *(num as *const i32 as *mut i32);
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
let _num = &mut *(num as *const i32).cast_mut();
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
let _num = *{ num as *const i32 }.cast_mut();
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
*std::ptr::from_ref(num).cast_mut() += 1;
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
*std::ptr::from_ref({ num }).cast_mut() += 1;
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
*{ std::ptr::from_ref(num) }.cast_mut() += 1;
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
*(std::ptr::from_ref({ num }) as *mut i32) += 1;
//~^ ERROR casting `&T` to `&mut T` is undefined behavior
// 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;
}
}
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