rust/src/libstd/num/u64.rs

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

//! Operations and constants for `u64`

use num::{CheckedAdd, CheckedSub};
#[cfg(target_word_size = "64")]
use num::CheckedMul;
use option::{Option, Some, None};
use unstable::intrinsics;

pub use self::generated::*;

uint_module!(u64, i64, 64)

impl CheckedAdd for u64 {
    #[inline]
    fn checked_add(&self, v: &u64) -> Option<u64> {
        unsafe {
            let (x, y) = intrinsics::u64_add_with_overflow(*self, *v);
            if y { None } else { Some(x) }
        }
    }
}

impl CheckedSub for u64 {
    #[inline]
    fn checked_sub(&self, v: &u64) -> Option<u64> {
        unsafe {
            let (x, y) = intrinsics::u64_sub_with_overflow(*self, *v);
            if y { None } else { Some(x) }
        }
    }
}

// FIXME: #8449: should not be disabled on 32-bit
#[cfg(target_word_size = "64")]
impl CheckedMul for u64 {
    #[inline]
    fn checked_mul(&self, v: &u64) -> Option<u64> {
        unsafe {
            let (x, y) = intrinsics::u64_mul_with_overflow(*self, *v);
            if y { None } else { Some(x) }
        }
    }
}