//! This crate provides types for identifying git objects using a hash digest.//!//! These are provided in [borrowed versions][oid] as well as an [owned one][ObjectId].//! ## Feature Flags#![cfg_attr(    all(doc, feature = "document-features"),    doc = ::document_features::document_features!())]#![cfg_attr(all(doc, feature = "document-features"), feature(doc_cfg))]#![deny(missing_docs, rust_2018_idioms, unsafe_code)] #[cfg(all(not(feature = "sha1"), not(feature = "sha256")))]compile_error!("Please set either the `sha1` or the `sha256` feature flag"); #[path = "oid.rs"]mod borrowed;pub use borrowed::{oid, Error}; /// Hash functions and hash utilitiespub mod hasher;pub use hasher::_impl::{hasher, Hasher}; /// Error types for utility hash functionspub mod io;pub use io::_impl::{bytes, bytes_of_file, bytes_with_hasher}; mod object_id;pub use object_id::{decode, ObjectId}; ///pub mod prefix; ///pub mod verify; /// A partial, owned hash possibly identifying an object uniquely, whose non-prefix bytes are zeroed.////// An example would `0000000000000000000000000000000032bd3242`, where `32bd3242` is the prefix,/// which would be able to match all hashes that *start with* `32bd3242`.#[derive(PartialEq, Eq, Hash, Ord, PartialOrd, Clone, Copy, Debug)]#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]pub struct Prefix {    bytes: ObjectId,    hex_len: usize,} /// The size of a SHA1 hash digest in bytes.#[cfg(feature = "sha1")]const SIZE_OF_SHA1_DIGEST: usize = 20;/// The size of a SHA1 hash digest in hex.#[cfg(feature = "sha1")]const SIZE_OF_SHA1_HEX_DIGEST: usize = 2 * SIZE_OF_SHA1_DIGEST; /// The size of a SHA256 hash digest in bytes.#[cfg(feature = "sha256")]const SIZE_OF_SHA256_DIGEST: usize = 32;/// The size of a SHA256 hash digest in hex.#[cfg(feature = "sha256")]const SIZE_OF_SHA256_HEX_DIGEST: usize = 2 * SIZE_OF_SHA256_DIGEST; #[cfg(feature = "sha1")]const EMPTY_BLOB_SHA1: &[u8; SIZE_OF_SHA1_DIGEST] =    b"\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91";#[cfg(feature = "sha1")]const EMPTY_TREE_SHA1: &[u8; SIZE_OF_SHA1_DIGEST] =    b"\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04"; #[cfg(feature = "sha256")]const EMPTY_BLOB_SHA256: &[u8; SIZE_OF_SHA256_DIGEST] = b"\x47\x3a\x0f\x4c\x3b\xe8\xa9\x36\x81\xa2\x67\xe3\xb1\xe9\xa7\xdc\xda\x11\x85\x43\x6f\xe1\x41\xf7\x74\x91\x20\xa3\x03\x72\x18\x13";#[cfg(feature = "sha256")]const EMPTY_TREE_SHA256: &[u8; SIZE_OF_SHA256_DIGEST] = b"\x6e\xf1\x9b\x41\x22\x5c\x53\x69\xf1\xc1\x04\xd4\x5d\x8d\x85\xef\xa9\xb0\x57\xb5\x3b\x14\xb4\xb9\xb9\x39\xdd\x74\xde\xcc\x53\x21"; /// Denotes the kind of function to produce a [`ObjectId`].#[derive(Default, PartialEq, Eq, Debug, Hash, Ord, PartialOrd, Clone, Copy)]#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]#[non_exhaustive]pub enum Kind {    /// The SHA1 hash with 160 bits.    #[cfg_attr(feature = "sha1", default)]    #[cfg(feature = "sha1")]    Sha1 = 1,    /// The SHA256 hash with 256 bits.    #[cfg_attr(all(not(feature = "sha1"), feature = "sha256"), default)]    #[cfg(feature = "sha256")]    Sha256 = 2,} mod kind;