cgmath/src/core/swap.rs

// Copyright 2013 The Lmath Developers. For a full listing of the authors,
// refer to the AUTHORS file at the top-level directory of this distribution.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use core::{Vec2, Vec3, Vec4, Quat};

pub trait Swap {
    pub fn swap(&mut self, a: uint, b: uint);
}

macro_rules! impl_swap(
    ($Self:ident) => (
        impl<T:Clone> Swap for $Self<T> {
            #[inline]
            pub fn swap(&mut self, a: uint, b: uint) {
                let tmp = self.index(a).clone();
                *self.index_mut(a) = self.index(b).clone();
                *self.index_mut(b) = tmp;
            }
        }
    )
)

impl_swap!(Vec2)
impl_swap!(Vec3)
impl_swap!(Vec4)
impl_swap!(Quat)

// This enclosing module is required because attributes don't play nice
// with macros yet
#[cfg(geom)]
pub mod geom_impls {
    use super::Swap;
    use geom::{Point2, Point3};

    impl_swap!(Point2)
    impl_swap!(Point3)
}

// This enclosing module is required because attributes don't play nice
// with macros yet
#[cfg(color)]
pub mod color_impls {
    use super::Swap;
    use color::{HSV, HSVA, YCbCr};
    use color::{RGB, RGBA, SRGB, SRGBA};

    impl_swap!(HSV)
    impl_swap!(HSVA)
    impl_swap!(RGB)
    impl_swap!(RGBA)
    impl_swap!(SRGB)
    impl_swap!(SRGBA)
    impl_swap!(YCbCr)
}