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//! 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.
//!
#![no_std]
#![cfg_attr(
feature = "nightly",
feature(
test,
core_intrinsics,
dropck_eyepatch,
min_specialization,
extend_one,
allocator_api,
slice_ptr_get,
maybe_uninit_array_assume_init,
strict_provenance
)
)]
#![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(internal_features))]
#[cfg(test)]
#[macro_use]
extern crate std;
#[cfg_attr(test, macro_use)]
extern crate alloc;
#[cfg(feature = "nightly")]
#[cfg(doctest)]
doc_comment::doctest!("../README.md");
#[macro_use]
mod macros;
#[cfg(feature = "raw")]
/// Experimental and unsafe `RawTable` API. This module is only available if the
/// `raw` feature is enabled.
pub mod raw {
// The RawTable API is still experimental and is not properly documented yet.
#[allow(missing_docs)]
#[path = "mod.rs"]
mod inner;
pub use inner::*;
#[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.
///
pub mod rayon {
pub use crate::external_trait_impls::rayon::raw::*;
}
}
#[cfg(not(feature = "raw"))]
mod raw;
mod external_trait_impls;
mod map;
#[cfg(feature = "rustc-internal-api")]
mod rustc_entry;
mod scopeguard;
mod set;
mod table;
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.
///
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.
///
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.
///
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,
},
}