79f52cf9ba
These are inspired by the [functions in the Julia standard library](http://docs.julialang.org/en/release-0.2/stdlib/base/#Base.count_ones).
72 lines
2.1 KiB
Rust
72 lines
2.1 KiB
Rust
// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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//! Operations and constants for signed 32-bits integers (`i32` type)
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#[allow(non_uppercase_statics)];
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use prelude::*;
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use default::Default;
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use num::{Bitwise, Bounded, CheckedAdd, CheckedSub, CheckedMul};
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use num::{CheckedDiv, Zero, One, strconv};
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use num::{ToStrRadix, FromStrRadix};
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use option::{Option, Some, None};
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use str;
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use unstable::intrinsics;
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int_module!(i32, 32)
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impl Bitwise for i32 {
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/// Returns the number of ones in the binary representation of the number.
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#[inline]
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fn count_ones(&self) -> i32 { unsafe { intrinsics::ctpop32(*self) } }
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/// Returns the number of leading zeros in the in the binary representation
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/// of the number.
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#[inline]
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fn leading_zeros(&self) -> i32 { unsafe { intrinsics::ctlz32(*self) } }
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/// Returns the number of trailing zeros in the in the binary representation
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/// of the number.
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#[inline]
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fn trailing_zeros(&self) -> i32 { unsafe { intrinsics::cttz32(*self) } }
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}
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impl CheckedAdd for i32 {
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#[inline]
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fn checked_add(&self, v: &i32) -> Option<i32> {
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unsafe {
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let (x, y) = intrinsics::i32_add_with_overflow(*self, *v);
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if y { None } else { Some(x) }
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}
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}
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}
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impl CheckedSub for i32 {
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#[inline]
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fn checked_sub(&self, v: &i32) -> Option<i32> {
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unsafe {
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let (x, y) = intrinsics::i32_sub_with_overflow(*self, *v);
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if y { None } else { Some(x) }
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}
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}
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}
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impl CheckedMul for i32 {
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#[inline]
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fn checked_mul(&self, v: &i32) -> Option<i32> {
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unsafe {
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let (x, y) = intrinsics::i32_mul_with_overflow(*self, *v);
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if y { None } else { Some(x) }
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}
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}
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}
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