#![feature(const_fn_transmute)] #![allow(dead_code)] extern crate core; use std::mem::transmute as my_transmute; use std::vec::Vec as MyVec; fn my_int() -> Usize { Usize(42) } fn my_vec() -> MyVec<i32> { vec![] } #[allow(clippy::needless_lifetimes, clippy::transmute_ptr_to_ptr)] #[warn(clippy::useless_transmute)] unsafe fn _generic<'a, T, U: 'a>(t: &'a T) { let _: &'a T = core::intrinsics::transmute(t); let _: &'a U = core::intrinsics::transmute(t); let _: *const T = core::intrinsics::transmute(t); let _: *mut T = core::intrinsics::transmute(t); let _: *const U = core::intrinsics::transmute(t); } #[warn(clippy::useless_transmute)] fn useless() { unsafe { let _: Vec<i32> = core::intrinsics::transmute(my_vec()); let _: Vec<i32> = core::mem::transmute(my_vec()); let _: Vec<i32> = std::intrinsics::transmute(my_vec()); let _: Vec<i32> = std::mem::transmute(my_vec()); let _: Vec<i32> = my_transmute(my_vec()); let _: *const usize = std::mem::transmute(5_isize); let _ = 5_isize as *const usize; let _: *const usize = std::mem::transmute(1 + 1usize); let _ = (1 + 1_usize) as *const usize; } } struct Usize(usize); #[warn(clippy::crosspointer_transmute)] fn crosspointer() { let mut int: Usize = Usize(0); let int_const_ptr: *const Usize = &int as *const Usize; let int_mut_ptr: *mut Usize = &mut int as *mut Usize; unsafe { let _: Usize = core::intrinsics::transmute(int_const_ptr); let _: Usize = core::intrinsics::transmute(int_mut_ptr); let _: *const Usize = core::intrinsics::transmute(my_int()); let _: *mut Usize = core::intrinsics::transmute(my_int()); } } #[warn(clippy::transmute_int_to_char)] fn int_to_char() { let _: char = unsafe { std::mem::transmute(0_u32) }; let _: char = unsafe { std::mem::transmute(0_i32) }; } #[warn(clippy::transmute_int_to_bool)] fn int_to_bool() { let _: bool = unsafe { std::mem::transmute(0_u8) }; } #[warn(clippy::transmute_int_to_float)] mod int_to_float { fn test() { let _: f32 = unsafe { std::mem::transmute(0_u32) }; let _: f32 = unsafe { std::mem::transmute(0_i32) }; let _: f64 = unsafe { std::mem::transmute(0_u64) }; let _: f64 = unsafe { std::mem::transmute(0_i64) }; } mod issue_5747 { const VALUE32: f32 = unsafe { std::mem::transmute(0_u32) }; const VALUE64: f64 = unsafe { std::mem::transmute(0_i64) }; const fn from_bits_32(v: i32) -> f32 { unsafe { std::mem::transmute(v) } } const fn from_bits_64(v: u64) -> f64 { unsafe { std::mem::transmute(v) } } } } fn bytes_to_str(b: &[u8], mb: &mut [u8]) { let _: &str = unsafe { std::mem::transmute(b) }; let _: &mut str = unsafe { std::mem::transmute(mb) }; } fn main() {}