internal.rs

// x11-rs: Rust bindings for X11 libraries
// The X11 libraries are available under the MIT license.
// These bindings are public domain.

use std::cmp::min;
use std::mem::{
  size_of,
  zeroed,
};


//
// public functions
//


pub unsafe fn mem_eq<T: Sized> (a: &T, b: &T) -> bool {
  let a_addr = a as *const T as usize;
  let b_addr = b as *const T as usize;

  for i in 0..size_of::<T>() {
    if *((a_addr + i) as *const u8) != *((b_addr + i) as *const u8) {
      return false;
    }
  }

  return true;
}

pub unsafe fn transmute_union<I, O> (input: &I) -> O
  where I : Sized, O : Sized
{
  let mut output: O = zeroed();
  let copy_len = min(size_of::<I>(), size_of::<O>());

  for i in 0..copy_len {
    *((&mut output as *mut O as usize + i) as *mut u8) = *((input as *const I as usize + i) as *const u8);
  }

  return output;
}