//! A helper trait to initialize a data structure with custom code.
//!
//! This crate is meant to aid in initializing fixed arrays using something other than a `Default`
//! implementation. For example, if you wanted to create an array of Vecs, you could create one
//! with `Default` that made all the Vecs empty:
//!
//! ```rust
//! let my_array = <[Vec<u32>; 3]>::default();
//! assert_eq!(my_array, [[], [], []]);
//! ```
//!
//! But if you wanted to start the arrays with some state, you either need to start with the empty
//! arrays and fill from there, or drop into unsafe code to write in a partially-initialized array.
//!
//! ```rust
//! let mut my_array = <[Vec<usize>; 3]>::default();
//!
//! for (idx, arr) in my_array.iter_mut().enumerate() {
//! for i in 0..(idx+1) {
//! arr.push(i);
//! }
//! }
//!
//! assert_eq!(my_array, [vec![0], vec![0, 1], vec![0, 1, 2]]);
//! ```
//!
//! With `InitWith`, the same array could be initialized like this:
//!
//! ```rust
//! use init_with::InitWith;
//!
//! let my_array = {
//! let mut seed = Vec::new();
//! let mut next_val = 0;
//!
//! <[Vec<u32>; 3]>::init_with(|| {
//! seed.push(next_val);
//! next_val += 1;
//! seed.clone()
//! })
//! };
//!
//! assert_eq!(my_array, [vec![0], vec![0, 1], vec![0, 1, 2]]);
//! ```
//!
//! **Warning**: If the function given to `init_with` panics, any elements that have already been
//! created will not run their destructor. This means that any elements with heap allocations -
//! `Vec`, `Box`, etc - will leak their contents.
//!
//! This crate is built with `#![no_std]` and only uses libcore for its code, so it can be used
//! from other `no_std` crates.
extern crate nodrop;
use ;
use NoDrop;
/// A trait that allows you to create an instance of a type with a given function.