#![warn(clippy::ref_as_ptr)]
#![allow(clippy::unnecessary_mut_passed)]

fn f<T>(_: T) {}

fn main() {
    f(std::ptr::from_ref(&1u8));
    f(std::ptr::from_ref::<u32>(&2u32));
    f(std::ptr::from_ref::<f64>(&3.0f64));

    f(std::ptr::from_ref(&4) as *const f32);
    f(std::ptr::from_ref::<f32>(&5.0f32) as *const u32);

    f(std::ptr::from_ref(&mut 6u8));
    f(std::ptr::from_ref::<u32>(&mut 7u32));
    f(std::ptr::from_ref::<f64>(&mut 8.0f64));

    f(std::ptr::from_ref(&mut 9) as *const f32);
    f(std::ptr::from_ref::<f32>(&mut 10.0f32) as *const u32);

    f(std::ptr::from_mut(&mut 11u8));
    f(std::ptr::from_mut::<u32>(&mut 12u32));
    f(std::ptr::from_mut::<f64>(&mut 13.0f64));

    f(std::ptr::from_mut(&mut 14) as *const f32);
    f(std::ptr::from_mut::<f32>(&mut 15.0f32) as *const u32);

    f(std::ptr::from_ref(&1u8));
    f(std::ptr::from_ref::<u32>(&2u32));
    f(std::ptr::from_ref::<f64>(&3.0f64));

    f(std::ptr::from_ref(&4) as *const f32);
    f(std::ptr::from_ref::<f32>(&5.0f32) as *const u32);

    let val = 1;
    f(std::ptr::from_ref(&val));
    f(std::ptr::from_ref::<i32>(&val));

    f(std::ptr::from_ref(&val) as *const f32);
    f(std::ptr::from_ref::<i32>(&val) as *const f64);

    let mut val: u8 = 2;
    f(std::ptr::from_mut::<u8>(&mut val));
    f(std::ptr::from_mut(&mut val));

    f(std::ptr::from_ref::<u8>(&mut val));
    f(std::ptr::from_ref(&mut val));

    f(std::ptr::from_ref::<u8>(&mut val) as *const f64);
    f::<*const Option<u8>>(std::ptr::from_ref(&mut val) as *const _);

    f(std::ptr::from_ref::<[usize; 7]>(&std::array::from_fn(|i| i * i)));
    f(std::ptr::from_ref::<[usize; 8]>(&mut std::array::from_fn(|i| i * i)));
    f(std::ptr::from_mut::<[usize; 9]>(&mut std::array::from_fn(|i| i * i)));

    let _ = &String::new() as *const _;
    let _ = &mut String::new() as *mut _;
    const FOO: *const String = &String::new() as *const _;
}

#[clippy::msrv = "1.75"]
fn _msrv_1_75() {
    let val = &42_i32;
    let mut_val = &mut 42_i32;

    // `std::ptr::from_{ref, mut}` was stabilized in 1.76. Do not lint this
    f(val as *const i32);
    f(mut_val as *mut i32);
}

#[clippy::msrv = "1.76"]
fn _msrv_1_76() {
    let val = &42_i32;
    let mut_val = &mut 42_i32;

    f(std::ptr::from_ref::<i32>(val));
    f(std::ptr::from_mut::<i32>(mut_val));
}

fn foo(val: &[u8]) {
    f(std::ptr::from_ref(val));
    f(std::ptr::from_ref::<[u8]>(val));
}

fn bar(val: &mut str) {
    f(std::ptr::from_mut(val));
    f(std::ptr::from_mut::<str>(val));
}

struct X<'a>(&'a i32);

impl<'a> X<'a> {
    fn foo(&self) -> *const i64 {
        std::ptr::from_ref(self.0) as *const _
    }

    fn bar(&mut self) -> *const i64 {
        std::ptr::from_ref(self.0) as *const _
    }
}

struct Y<'a>(&'a mut i32);

impl<'a> Y<'a> {
    fn foo(&self) -> *const i64 {
        std::ptr::from_ref(self.0) as *const _
    }

    fn bar(&mut self) -> *const i64 {
        std::ptr::from_ref(self.0) as *const _
    }

    fn baz(&mut self) -> *const i64 {
        std::ptr::from_mut(self.0) as *mut _
    }
}