//! This crate is a Rust port of Google's high-performance [SwissTable] hash

//! map, adapted to make it a drop-in replacement for Rust's standard `HashMap`

//! and `HashSet` types.

//!

//! The original C++ version of [SwissTable] can be found [here], and this

//! [CppCon talk] gives an overview of how the algorithm works.

//!

//! [SwissTable]: https://abseil.io/blog/20180927-swisstables

//! [here]: https://github.com/abseil/abseil-cpp/blob/master/absl/container/internal/raw_hash_set.h

//! [CppCon talk]: https://www.youtube.com/watch?v=ncHmEUmJZf4

#![no_std]

#![cfg_attr(

    feature = "nightly",

    feature(

        test,

        core_intrinsics,

        dropck_eyepatch,

        min_specialization,

        trivial_clone,

        extend_one,

        allocator_api,

        slice_ptr_get,

        maybe_uninit_array_assume_init,

        strict_provenance_lints

    )

)]

#![cfg_attr(feature = "rustc-dep-of-std", feature(rustc_attrs))]

#![allow(

    clippy::doc_markdown,

    clippy::module_name_repetitions,

    clippy::must_use_candidate,

    clippy::option_if_let_else,

    clippy::redundant_else,

    clippy::manual_map,

    clippy::missing_safety_doc,

    clippy::missing_errors_doc

)]

#![warn(missing_docs)]

#![warn(rust_2018_idioms)]

#![cfg_attr(feature = "nightly", warn(fuzzy_provenance_casts))]

#![cfg_attr(

    feature = "nightly",

    allow(clippy::incompatible_msrv, internal_features)

)]

#![cfg_attr(

    all(feature = "nightly", target_arch = "loongarch64"),

    feature(stdarch_loongarch)

)]

#![cfg_attr(

    all(feature = "nightly", feature = "default-hasher"),

    feature(hasher_prefixfree_extras)

)]

#[cfg(test)]

#[macro_use]

extern crate std;

#[cfg_attr(test, macro_use)]

#[cfg_attr(feature = "rustc-dep-of-std", allow(unused_extern_crates))]

extern crate alloc;

#[doc = include_str!("../README.md")]

#[cfg(doctest)]

pub struct ReadmeDoctests;

#[macro_use]

mod macros;

mod control;

mod hasher;

mod raw;

mod util;

mod external_trait_impls;

mod map;

#[cfg(feature = "raw-entry")]

mod raw_entry;

#[cfg(feature = "rustc-internal-api")]

mod rustc_entry;

mod scopeguard;

mod set;

mod table;

pub use crate::hasher::DefaultHashBuilder;

#[cfg(feature = "default-hasher")]

pub use crate::hasher::DefaultHasher;

pub mod hash_map {

    //! A hash map implemented with quadratic probing and SIMD lookup.

    pub use crate::map::*;

    #[cfg(feature = "rustc-internal-api")]

    pub use crate::rustc_entry::*;

    #[cfg(feature = "rayon")]

    /// [rayon]-based parallel iterator types for hash maps.

    /// You will rarely need to interact with it directly unless you have need

    /// to name one of the iterator types.

    ///

    /// [rayon]: https://docs.rs/rayon/1.0/rayon

    pub mod rayon {

        pub use crate::external_trait_impls::rayon::map::*;

    }

}

pub mod hash_set {

    //! A hash set implemented as a `HashMap` where the value is `()`.

    pub use crate::set::*;

    #[cfg(feature = "rayon")]

    /// [rayon]-based parallel iterator types for hash sets.

    /// You will rarely need to interact with it directly unless you have need

    /// to name one of the iterator types.

    ///

    /// [rayon]: https://docs.rs/rayon/1.0/rayon

    pub mod rayon {

        pub use crate::external_trait_impls::rayon::set::*;

    }

}

pub mod hash_table {

    //! A hash table implemented with quadratic probing and SIMD lookup.

    pub use crate::table::*;

    #[cfg(feature = "rayon")]

    /// [rayon]-based parallel iterator types for hash tables.

    /// You will rarely need to interact with it directly unless you have need

    /// to name one of the iterator types.

    ///

    /// [rayon]: https://docs.rs/rayon/1.0/rayon

    pub mod rayon {

        pub use crate::external_trait_impls::rayon::table::*;

    }

}

pub use crate::map::HashMap;

pub use crate::set::HashSet;

pub use crate::table::HashTable;

#[cfg(feature = "equivalent")]

pub use equivalent::Equivalent;

// This is only used as a fallback when building as part of `std`.

#[cfg(not(feature = "equivalent"))]

/// Key equivalence trait.

///

/// This trait defines the function used to compare the input value with the

/// map keys (or set values) during a lookup operation such as [`HashMap::get`]

/// or [`HashSet::contains`].

/// It is provided with a blanket implementation based on the

/// [`Borrow`](core::borrow::Borrow) trait.

///

/// # Correctness

///

/// Equivalent values must hash to the same value.

pub trait Equivalent<K: ?Sized> {

    /// Checks if this value is equivalent to the given key.

    ///

    /// Returns `true` if both values are equivalent, and `false` otherwise.

    ///

    /// # Correctness

    ///

    /// When this function returns `true`, both `self` and `key` must hash to

    /// the same value.

    fn equivalent(&self, key: &K) -> bool;

}

#[cfg(not(feature = "equivalent"))]

impl<Q: ?Sized, K: ?Sized> Equivalent<K> for Q

where

    Q: Eq,

    K: core::borrow::Borrow<Q>,

{

    fn equivalent(&self, key: &K) -> bool {

        self == key.borrow()

    }

}

/// The error type for `try_reserve` methods.

#[derive(Clone, PartialEq, Eq, Debug)]

pub enum TryReserveError {

    /// Error due to the computed capacity exceeding the collection's maximum

    /// (usually `isize::MAX` bytes).

    CapacityOverflow,

    /// The memory allocator returned an error

    AllocError {

        /// The layout of the allocation request that failed.

        layout: alloc::alloc::Layout,

    },

}