// Copyright (c) 2017 Gilad Naaman

//

// Permission is hereby granted, free of charge, to any person obtaining a copy

// of this software and associated documentation files (the "Software"), to deal

// in the Software without restriction, including without limitation the rights

// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

// copies of the Software, and to permit persons to whom the Software is

// furnished to do so, subject to the following conditions:

//

// The above copyright notice and this permission notice shall be included in all

// copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

// SOFTWARE.

//! A crate used for calculating offsets of struct members and their spans.

//!

//! This functionality currently can not be used in compile time code such as `const` or `const fn` definitions.

//!

//! ## Examples

//! ```

//! use memoffset::{offset_of, span_of};

//!

//! #[repr(C, packed)]

//! struct HelpMeIAmTrappedInAStructFactory {

//!     help_me_before_they_: [u8; 15],

//!     a: u32

//! }

//!

//! fn main() {

//!     assert_eq!(offset_of!(HelpMeIAmTrappedInAStructFactory, a), 15);

//!     assert_eq!(span_of!(HelpMeIAmTrappedInAStructFactory, a), 15..19);

//!     assert_eq!(span_of!(HelpMeIAmTrappedInAStructFactory, help_me_before_they_ .. a), 0..15);

//! }

//! ```

//!

//! This functionality can be useful, for example, for checksum calculations:

//!

//! ```ignore

//! #[repr(C, packed)]

//! struct Message {

//!     header: MessageHeader,

//!     fragment_index: u32,

//!     fragment_count: u32,

//!     payload: [u8; 1024],

//!     checksum: u16

//! }

//!

//! let checksum_range = &raw[span_of!(Message, header..checksum)];

//! let checksum = crc16(checksum_range);

//! ```

#![no_std]

#![cfg_attr(

    all(feature = "unstable_const", not(stable_const)),

    feature(const_ptr_offset_from)

)]

#![cfg_attr(feature = "unstable_const", feature(const_refs_to_cell))]

#![cfg_attr(feature = "unstable_offset_of", feature(allow_internal_unstable))]

#[macro_use]

#[cfg(doctests)]

#[cfg(doctest)]

extern crate doc_comment;

#[cfg(doctests)]

#[cfg(doctest)]

doctest!("../README.md");

/// Hidden module for things the macros need to access.

#[doc(hidden)]

pub mod __priv {

    #[doc(hidden)]

    pub use core::mem;

    #[doc(hidden)]

    pub use core::ptr;

    /// Use type inference to obtain the size of the pointee (without actually using the pointer).

    #[doc(hidden)]

    pub fn size_of_pointee<T>(_ptr: *const T) -> usize {

        mem::size_of::<T>()

    }

}

#[macro_use]

mod raw_field;

#[macro_use]

mod offset_of;

#[macro_use]

mod span_of;