// Copyright 2016 bluss and ndarray developers.

//

// 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.

/// An axis index.

///

/// An axis one of an array’s “dimensions”; an *n*-dimensional array has *n*

/// axes.  Axis *0* is the array’s outermost axis and *n*-1 is the innermost.

///

/// All array axis arguments use this type to make the code easier to write

/// correctly and easier to understand.

///

/// For example: in a method like `index_axis(axis, index)` the code becomes

/// self-explanatory when it's called like `.index_axis(Axis(1), i)`; it's

/// evident which integer is the axis number and which is the index.

///

/// Note: This type does **not** implement From/Into usize and similar trait

/// based conversions, because we want to preserve code readability and quality.

///

/// `Axis(1)` in itself is a very clear code style and the style that should be

/// avoided is code like `1.into()`.

#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]

pub struct Axis(pub usize);

impl Axis

{

    /// Return the index of the axis.

    #[inline(always)]

    pub fn index(self) -> usize

    {

        self.0

    }

}