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//! Runtime managed resource borrowing.
//!
//! This library provides a map that can store one of any type, as well as
//! mutable borrows to each type at the same time.
//!
//! **Note:** This implementation is extracted from [`shred`], with the
//! following differences:
//!
//! * Uses [`downcast-rs`] instead of [`mopa`] for downcasting types.
//! * Adds `Debug` and `PartialEq` implementations for borrow types when the
//!   resource type implements those traits.
//! * Returns `None` instead of panicking for `try_borrow*` functions when the
//!   resource is already borrowed.
//!
//! ## Usage
//!
//! Add the following to `Cargo.toml`
//!
//! ```toml
//! resman = "0.1.0"
//! ```
//!
//! In code:
//!
//! ```rust
//! use resman::Resources;
//!
//! struct A(u32);
//! struct B(u32);
//!
//! let mut resources = Resources::default();
//!
//! resources.insert(A(1));
//! resources.insert(B(2));
//!
//! // We can validly have two mutable borrows from the `Resources` map!
//! let mut a = resources.borrow_mut::<A>();
//! let mut b = resources.borrow_mut::<B>();
//! a.0 = 2;
//! b.0 = 3;
//!
//! // We need to explicitly drop the A and B borrows, because they are runtime
//! // managed borrows, and rustc doesn't know to drop them before the immutable
//! // borrows after this.
//! drop(a);
//! drop(b);
//!
//! // Multiple immutable borrows to the same resource are valid.
//! let a_0 = resources.borrow::<A>();
//! let _a_1 = resources.borrow::<A>();
//! let b = resources.borrow::<B>();
//!
//! println!("A: {}", a_0.0);
//! println!("B: {}", b.0);
//!
//! // Trying to mutably borrow a resource that is already borrowed (immutably
//! // or mutably) returns `None`.
//! let a_try_borrow_mut = resources.try_borrow_mut::<A>();
//! let exists = if a_try_borrow_mut.is_some() {
//!     "Some(..)"
//! } else {
//!     "None"
//! };
//! println!("a_try_borrow_mut: {}", exists); // prints "None"
//! ```
//!
//! ## See Also
//!
//! * [`anymap`]: Map of any type, without multiple mutable borrows.
//! * [`shred`]: Contains `Resources` type, plus a task dispatcher.
//!
//! [`anymap`]: https://github.com/chris-morgan/anymap
//! [`downcast-rs`]: https://github.com/marcianx/downcast-rs
//! [`mopa`]: https://github.com/chris-morgan/mopa
//! [`shred`]: https://github.com/amethyst/shred

pub use crate::{
    entry::Entry, r#ref::Ref, ref_mut::RefMut, resource::Resource, resources::Resources,
};

mod entry;
mod r#ref;
mod ref_mut;
mod resource;
mod resources;