const-hex

https://docs.rs/const-hex/latest/
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const-hex is a fast Rust crate for converting byte arrays to hexadecimal strings at compile time and...
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### Buffer Initialization and Formatting Example (Rust)

Source: https://docs.rs/const-hex/latest/const_hex/struct

Demonstrates how to create a `Buffer` instance and use its `format` method to convert a byte array into its lower-case hexadecimal string representation.

```Rust
let mut buffer = const_hex::Buffer::<4>::new();
let printed = buffer.format(b"1234");
assert_eq!(printed, "31323334");
```

--------------------------------

### Rust Example: Encoding String to Hex

Source: https://docs.rs/const-hex/latest/const_hex/trait

Demonstrates how to use the `ToHex` trait to encode a string into its hexadecimal representation. This example shows a common use case for the trait.

```Rust
use hex::ToHex;

println!("{}", "Hello world!".encode_hex::<String>());
```

--------------------------------

### Buffer Initialization and Default in Rust

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Provides the `new` and `default` methods for the Buffer struct. `new` creates a Buffer instance, initializing the prefix based on the `PREFIX` const generic and filling the byte array with zeros. `default` provides a convenient way to get a default Buffer.

```rust
impl<const N: usize, const PREFIX: bool> Default for Buffer<N, PREFIX> {
    #[inline]
    fn default() -> Self {
        Self::new()
    }
}

impl<const N: usize, const PREFIX: bool> Buffer<N, PREFIX> {
    /// The length of the buffer in bytes.
    pub const LEN: usize = (N + PREFIX as usize) * 2;

    const ASSERT_SIZE: () = assert!(core::mem::size_of::<Self>() == 2 + N * 2, "invalid size");
    const ASSERT_ALIGNMENT: () = assert!(core::mem::align_of::<Self>() == 1, "invalid alignment");

    /// This is a cheap operation; you don't need to worry about reusing buffers
    /// for efficiency.
    #[inline]
    pub const fn new() -> Self {
        let () = Self::ASSERT_SIZE;
        let () = Self::ASSERT_ALIGNMENT;
        Self {
            prefix: if PREFIX { [b'0', b'x'] } else { [0, 0] },
            bytes: [[0; 2]; N],
        }
    }
}
```

--------------------------------

### Rust Examples for ToHex Trait Usage

Source: https://docs.rs/const-hex/latest/const_hex/traits/trait

Demonstrates how to use the deprecated `ToHex` trait to encode a string into its hexadecimal representation, both in lowercase and uppercase. The examples show the expected output for the ASCII string 'Hello world!'.

```Rust
#![allow(deprecated)]
use const_hex::ToHex;

assert_eq!("Hello world!".encode_hex::<String>(), "48656c6c6f20776f726c6421");
assert_eq!("Hello world!".encode_hex_upper::<String>(), "48656C6C6F20776F726C6421");
```

--------------------------------

### Serde Example: Struct with Hex Field

Source: https://docs.rs/const-hex/latest/src/const_hex/serde

Demonstrates how to use the `#[serde(with = "const_hex")]` attribute to automatically serialize and deserialize a `Vec<u8>` field as a hex string within a struct.

```rust
# #[cfg(feature = "alloc")] {
use serde::{Serialize, Deserialize};

#[derive(Serialize, Deserialize)]
struct Foo {
    #[serde(with = "const_hex")]
    bar: Vec<u8>,
}
# }

```

--------------------------------

### Get Raw Pointer to Buffer (Rust)

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Returns a const raw pointer to the buffer. The caller must ensure the buffer outlives the pointer. It calculates the pointer offset based on the `PREFIX` constant.

```Rust
    /// Returns a raw pointer to the buffer.
    ///
    /// The caller must ensure that the buffer outlives the pointer this
    /// function returns, or else it will end up pointing to garbage.
    #[inline]
    pub const fn as_ptr(&self) -> *const u8 {
        unsafe { (self as *const Self).cast::<u8>().add(!PREFIX as usize * 2) }
    }
```

--------------------------------

### Get Mutable Raw Pointer to Buffer (Rust)

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Returns a mutable raw pointer to the buffer's slice. The caller must ensure the slice outlives the pointer. It calculates the pointer offset based on the `PREFIX` constant.

```Rust
    /// Returns an unsafe mutable pointer to the slice's buffer.
    ///
    /// The caller must ensure that the slice outlives the pointer this
    /// function returns, or else it will end up pointing to garbage.
    #[inline]
    pub fn as_mut_ptr(&mut self) -> *mut u8 {
        unsafe { (self as *mut Self).cast::<u8>().add(!PREFIX as usize * 2) }
    }
```

--------------------------------

### Get Buffer as Byte Slice (Rust)

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Returns a const reference to the underlying bytes as a slice. This const method uses unsafe code to create the slice from a raw pointer, leveraging layout compatibility.

```Rust
    /// Returns a reference to the underlying bytes.
    #[inline]
    pub const fn as_bytes(&self) -> &[u8] {
        // SAFETY: [u16; N] is layout-compatible with [u8; N * 2].
        unsafe { slice::from_raw_parts(self.as_ptr(), Self::LEN) }
    }
```

--------------------------------

### Rust: Get Hex Character Lookup Table

Source: https://docs.rs/const-hex/latest/src/const_hex/lib

Returns a reference to a static array of 16 bytes representing hexadecimal characters ('0'-'9', 'a'-'f' or 'A'-'F'). The choice between lowercase and uppercase tables is determined by the `UPPER` const generic parameter.

```rust
#[inline(always)]
const fn get_chars_table<const UPPER: bool>() -> &'static [u8; 16] {
    if UPPER {
        HEX_CHARS_UPPER
    } else {
        HEX_CHARS_LOWER
    }
}
```

--------------------------------

### Get Buffer as Byte Array (Rust)

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Returns a reference to the underlying stack-allocated byte array with a specified length. This const function includes a compile-time assertion to ensure the provided length matches the buffer's expected length. It uses unsafe code for casting the pointer, leveraging layout compatibility between [u16; N] and [u8; N * 2].

```Rust
    /// Returns a reference to the underlying stack-allocated byte array.
    ///
    /// # Panics
    ///
    /// If `LEN` does not equal `Self::LEN`.
    ///
    /// This is panic is evaluated at compile-time if the `nightly` feature
    /// is enabled, as inline `const` blocks are currently unstable.
    ///
    /// See Rust tracking issue [#76001](https://github.com/rust-lang/rust/issues/76001).
    #[inline]
    pub const fn as_byte_array<const LEN: usize>(&self) -> &[u8; LEN] {
        maybe_const_assert!(LEN == Self::LEN, "`LEN` must be equal to `Self::LEN`");
        // SAFETY: [u16; N] is layout-compatible with [u8; N * 2].
        unsafe { &*self.as_ptr().cast::<[u8; LEN]>() }
    }
```

--------------------------------

### Implement PartialEq for FromHexError

Source: https://docs.rs/const-hex/latest/const_hex/enum

Shows the implementation of `PartialEq` for `FromHexError`, enabling comparison of error instances for equality and inequality.

```rust
impl PartialEq for FromHexError
Source
#### fn eq(&self, other: &FromHexError) -> bool
Tests for `self` and `other` values to be equal, and is used by `==`.
1.0.0 · Source
#### fn ne(&self, other: &Rhs) -> bool
Tests for `!=`. The default implementation is almost always sufficient, and should not be overridden without very good reason.
Source
```

--------------------------------

### Buffer Constants and Methods (Rust)

Source: https://docs.rs/const-hex/latest/const_hex/struct

Details the `LEN` constant, `new` constructor, and various formatting methods (`const_format`, `const_format_upper`, `format`, `format_upper`, `format_slice`, `format_slice_upper`) for the `Buffer` struct.

```Rust
pub const LEN: usize

pub const fn new() -> Self

pub const fn const_format(self, array: &[u8; N]) -> Self

pub const fn const_format_upper(self, array: &[u8; N]) -> Self

pub fn format(&mut self, array: &[u8; N]) -> &mut str

pub fn format_upper(&mut self, array: &[u8; N]) -> &mut str

pub fn format_slice<T: AsRef<[u8]>>(&mut self, slice: T) -> &mut str

pub fn format_slice_upper<T: AsRef<[u8]>>(&mut self, slice: T) -> &mut str
```

--------------------------------

### Get Mutable Buffer Excluding Prefix (Rust)

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Returns a mutable reference to the underlying buffer, excluding the prefix bytes. This method is unsafe and requires the caller to ensure UTF-8 validity, similar to `as_mut_bytes`.

```Rust
    /// Returns a mutable reference to the underlying buffer, excluding the prefix.
    ///
    /// # Safety
    ///
    /// See [`as_mut_bytes`](Buffer::as_mut_bytes).
    #[inline]
    pub unsafe fn buffer(&mut self) -> &mut [u8] {
        unsafe { slice::from_raw_parts_mut(self.bytes.as_mut_ptr().cast(), N * 2) }
    }
```

--------------------------------

### CloneToUninit Experimental Copy-Assignment

Source: https://docs.rs/const-hex/latest/const_hex/struct

Provides an experimental, nightly-only `clone_to_uninit` method for types implementing `Clone`. This method performs copy-assignment from `self` to a raw pointer `dest` in uninitialized memory.

```rust
unsafe fn clone_to_uninit(&self, dest: *mut u8)
```

--------------------------------

### Implement StructuralPartialEq for FromHexError

Source: https://docs.rs/const-hex/latest/const_hex/enum

Demonstrates the implementation of `StructuralPartialEq` for `FromHexError`, used for structural equality comparisons.

```rust
impl StructuralPartialEq for FromHexError
```

--------------------------------

### Implement Blanket Trait: CloneToUninit

Source: https://docs.rs/const-hex/latest/const_hex/enum

Shows the blanket implementation of the experimental `CloneToUninit` trait, facilitating copying data to uninitialized memory.

```rust
impl<T> CloneToUninit for T
where T: Clone,
Source
#### unsafe fn clone_to_uninit(&self, dest: *mut u8)
🔬This is a nightly-only experimental API. (`clone_to_uninit`)
Performs copy-assignment from `self` to `dest`. Read more
Source
```

--------------------------------

### Get Buffer as String Slice (Rust)

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Returns a reference to the underlying bytes casted to a string slice. This method is inlined and uses an unsafe operation, assuming the buffer always contains valid UTF-8.

```Rust
    /// Returns a reference to the underlying bytes casted to a string slice.
    #[inline]
    pub const fn as_str(&self) -> &str {
        // SAFETY: The buffer always contains valid UTF-8.
        unsafe { str::from_utf8_unchecked(self.as_bytes()) }
    }
```

--------------------------------

### Buffer Debug and AsRef Implementations in Rust

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Implements `Debug` and `AsRef<str>` for the Buffer struct. The `Debug` implementation formats the buffer as a tuple containing its string representation. The `AsRef<str>` implementation provides a convenient way to access the hex-formatted string as a `&str`.

```rust
impl<const N: usize, const PREFIX: bool> fmt::Debug for Buffer<N, PREFIX> {
    #[inline]
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_tuple("Buffer").field(&self.as_str()).finish()
    }
}

impl<const N: usize, const PREFIX: bool> AsRef<str> for Buffer<N, PREFIX> {
    #[inline]
    fn as_ref(&self) -> &str {
        self.as_str()
    }
}
```

--------------------------------

### Buffer Trait Implementations (Rust)

Source: https://docs.rs/const-hex/latest/const_hex/struct

Shows implementations of standard Rust traits for the `Buffer` struct, including `AsRef<str>`, `Clone`, and `Debug`, enabling common operations like string conversion and debugging.

```Rust
impl<const N: usize, const PREFIX: bool> AsRef<str> for Buffer<N, PREFIX>
fn as_ref(&self) -> &str

impl<const N: usize, const PREFIX: bool> Clone for Buffer<N, PREFIX>
fn clone(&self) -> Buffer<N, PREFIX>
fn clone_from(&mut self, source: &Self)

impl<const N: usize, const PREFIX: bool> Debug for Buffer<N, PREFIX>
```

--------------------------------

### Get Mutable Buffer as Byte Slice (Rust)

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Returns a mutable reference to the underlying bytes as a slice. This method requires `unsafe` due to direct memory manipulation and includes safety notes regarding UTF-8 validity.

```Rust
    /// Returns a mutable reference to the underlying bytes.
    ///
    /// # Safety
    ///
    /// The caller must ensure that the content of the slice is valid UTF-8
    /// before the borrow ends and the underlying `str` is used.
    ///
    /// Use of a `str` whose contents are not valid UTF-8 is undefined behavior.
    #[inline]
    pub unsafe fn as_mut_bytes(&mut self) -> &mut [u8] {
        // SAFETY: [u16; N] is layout-compatible with [u8; N * 2].
        unsafe { slice::from_raw_parts_mut(self.as_mut_ptr(), Self::LEN) }
    }
```

--------------------------------

### Get Mutable Buffer as String Slice (Rust)

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Returns a mutable reference to the underlying bytes casted to a string slice. This method is inlined and uses an unsafe operation, assuming the buffer always contains valid UTF-8.

```Rust
    /// Returns a mutable reference to the underlying bytes casted to a string
    /// slice.
    #[inline]
    pub fn as_mut_str(&mut self) -> &mut str {
        // SAFETY: The buffer always contains valid UTF-8.
        unsafe { str::from_utf8_unchecked_mut(self.as_mut_bytes()) }
    }
```

--------------------------------

### Buffer Formatting

Source: https://docs.rs/const-hex/latest/const_hex/struct

Implements the `fmt` method for the `Buffer` type, allowing it to be formatted using a given `Formatter`. This is essential for displaying buffer contents in a human-readable format.

```rust
fn fmt(&self, f: &mut Formatter<'_>) -> Result
```

--------------------------------

### Get Mutable Buffer as Byte Array (Rust)

Source: https://docs.rs/const-hex/latest/src/const_hex/buffer

Returns a mutable reference to the underlying stack-allocated byte array with a specified length. This method includes a compile-time assertion for length matching and uses unsafe code for pointer casting, similar to `as_byte_array`.

```Rust
    /// Returns a mutable reference the underlying stack-allocated byte array.
    ///
    /// # Panics
    ///
    /// If `LEN` does not equal `Self::LEN`.
    ///
    /// See [`as_byte_array`](Buffer::as_byte_array) for more information.
    #[inline]
    pub fn as_mut_byte_array<const LEN: usize>(&mut self) -> &mut [u8; LEN] {
        maybe_const_assert!(LEN == Self::LEN, "`LEN` must be equal to `Self::LEN`");
        // SAFETY: [u16; N] is layout-compatible with [u8; N * 2].
        unsafe { &mut *self.as_mut_ptr().cast::<[u8; LEN]>() }
    }
```

--------------------------------

### Serde Integration with const_hex

Source: https://docs.rs/const-hex/latest/const_hex/serde/index

Demonstrates how to use the `const_hex` module with serde for serializing and deserializing byte vectors as hex strings. Requires the `serde` crate.

```rust
use serde::{Serialize, Deserialize};

#[derive(Serialize, Deserialize)]
struct Foo {
    #[serde(with = "const_hex")]
    bar: Vec<u8>,
}

```

--------------------------------

### Implement Display for FromHexError

Source: https://docs.rs/const-hex/latest/const_hex/enum

Illustrates the implementation of the `Display` trait for `FromHexError`, providing a user-friendly string representation of the error.

```rust
impl Display for FromHexError
Source
#### fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
Formats the value using the given formatter. Read more
Source
```

--------------------------------

### Rust: Strip 0x Prefix from Byte Slice

Source: https://docs.rs/const-hex/latest/src/const_hex/lib

A constant function that removes the "0x" prefix from a byte slice if it exists. If the slice starts with `b'0'` followed by `b'x'`, it returns a slice of the remaining bytes; otherwise, it returns the original slice.

```rust
#[inline]
const fn strip_prefix(bytes: &[u8]) -> &[u8] {
    match bytes {
        [b'0', b'x', rest @ ..] => rest,
        _ => bytes,
    }
}
```

--------------------------------

### Rust: Hex Encoding with `serde` (Serialization)

Source: https://docs.rs/const-hex/latest/const_hex/index

Handles hexadecimal encoding for types that are being serialized using the `serde` framework. This allows seamless integration with `serde`.

```Rust
pub fn serialize<T: ?Sized + ToHex>(value: &T) -> impl serde::Serialize;

```

--------------------------------

### FromHex Implementations

Source: https://docs.rs/const-hex/latest/src/const_hex/traits

Demonstrates how the `FromHex` trait is implemented for common types like `Vec<u8>`, `Box<[u8]>`, and fixed-size arrays `[u8; N]`.

```APIDOC
## Implementations of FromHex Trait

### Description
This section details the implementations of the `FromHex` trait for various Rust types, including dynamically sized vectors and fixed-size arrays.

### `Vec<u8>`

#### Method
`from_hex<T: AsRef<[u8]>>(hex: T) -> Result<Vec<u8>, crate::FromHexError>`

#### Description
Decodes a hexadecimal string into a `Vec<u8>`.

#### Request Example
```rust
use const_hex::FromHex;

let bytes: Vec<u8> = <Vec<u8>>::from_hex("48656c6c6f")?;
// bytes will be vec![72, 101, 108, 108, 111]
```

### `Vec<i8>`

#### Method
`from_hex<T: AsRef<[u8]>>(hex: T) -> Result<Vec<i8>, crate::FromHexError>`

#### Description
Decodes a hexadecimal string into a `Vec<i8>`. This involves a transmute operation after decoding to `Vec<u8>`.

#### Request Example
```rust
use const_hex::FromHex;

let signed_bytes: Vec<i8> = <Vec<i8>>::from_hex("FF00")?;
// signed_bytes will be vec![-1, 0]
```

### `Box<[u8]>`

#### Method
`from_hex<T: AsRef<[u8]>>(hex: T) -> Result<Box<[u8]>, crate::FromHexError>`

#### Description
Decodes a hexadecimal string into a `Box<[u8]>`.

#### Request Example
```rust
use const_hex::FromHex;

let boxed_bytes: Box<[u8]> = <Box<[u8]>>::from_hex("0a0b0c")?;
// boxed_bytes will be Box::new([10, 11, 12])
```

### `Box<[i8]>`

#### Method
`from_hex<T: AsRef<[u8]>>(hex: T) -> Result<Box<[i8]>, crate::FromHexError>`

#### Description
Decodes a hexadecimal string into a `Box<[i8]>`.

#### Request Example
```rust
use const_hex::FromHex;

let boxed_signed_bytes: Box<[i8]> = <Box<[i8]>>::from_hex("80")?;
// boxed_signed_bytes will be Box::new([-128])
```

### `[u8; N]` (Generic Array)

#### Method
`from_hex<T: AsRef<[u8]>>(hex: T) -> Result<[u8; N], crate::FromHexError>`

#### Description
Decodes a hexadecimal string into a fixed-size byte array `[u8; N]`. The length of the decoded hex string must match `N`.

#### Request Example
```rust
use const_hex::FromHex;

let arr: [u8; 3] = <[u8; 3]>::from_hex("010203")?;
// arr will be [1, 2, 3]
```

### `[i8; N]` (Generic Signed Array)

#### Method
`from_hex<T: AsRef<[u8]>>(hex: T) -> Result<[i8; N], crate::FromHexError>`

#### Description
Decodes a hexadecimal string into a fixed-size signed byte array `[i8; N]`.

#### Request Example
```rust
use const_hex::FromHex;

let signed_arr: [i8; 2] = <[i8; 2]>::from_hex("8180")?;
// signed_arr will be [129, -128] (Note: 129 in u8 is -127 in i8, but here it's raw byte interpretation)
```

### `Box<T>` where `T: FromHex`

#### Method
`from_hex<U: AsRef<[u8]>>(hex: U) -> Result<Box<Self>, Self::Error>`

#### Description
Decodes a hexadecimal string and returns it wrapped in a `Box`.

### `Cow<'_, T>` where `T: ToOwned + ?Sized` and `T::Owned: FromHex`

#### Method
`from_hex<U: AsRef<[u8]>>(hex: U) -> Result<Cow<'_, Self>, Self::Error>`

#### Description
Decodes a hexadecimal string into an owned `Cow`.

### `Rc<T>` where `T: FromHex`

#### Method
`from_hex<U: AsRef<[u8]>>(hex: U) -> Result<Rc<Self>, Self::Error>`

#### Description
Decodes a hexadecimal string and returns it wrapped in an `Rc`.

### `Arc<T>` where `T: FromHex`

#### Method
`from_hex<U: AsRef<[u8]>>(hex: U) -> Result<Arc<Self>, Self::Error>`

#### Description
Decodes a hexadecimal string and returns it wrapped in an `Arc`.
```

--------------------------------

### Rust: Fuzzing Utilities for Hex Encoding/Decoding

Source: https://docs.rs/const-hex/latest/src/const_hex/lib

Provides fuzzing functions (`fuzz`, `encode`, `decode`) for testing hex encoding and decoding logic. These functions use `proptest` to generate test cases and assert correctness against expected outputs and round-trip conversions. They are conditionally compiled under the `__fuzzing` feature flag and exclude Miri testing.

```rust
#[allow(
    missing_docs,
    unused,
    clippy::all,
    clippy::missing_inline_in_public_items
)]
#[cfg(all(feature = "__fuzzing", not(miri)))]
#[doc(hidden)]
pub mod fuzzing {
    use super::*;
    use proptest::test_runner::TestCaseResult;
    use proptest::{prop_assert, prop_assert_eq};
    use std::fmt::Write;

    pub fn fuzz(data: &[u8]) -> TestCaseResult {
        self::encode(&data)?;
        self::decode(&data)?;
        Ok(())
    }

    pub fn encode(input: &[u8]) -> TestCaseResult {
        test_buffer::<8, 16>(input)?;
        test_buffer::<20, 40>(input)?;
        test_buffer::<32, 64>(input)?;
        test_buffer::<64, 128>(input)?;
        test_buffer::<128, 256>(input)?;

        let encoded = crate::encode(input);
        let expected = mk_expected(input);
        prop_assert_eq!(&encoded, &expected);

        let decoded = crate::decode(&encoded).unwrap();
        prop_assert_eq!(decoded, input);

        Ok(())
    }

    pub fn decode(input: &[u8]) -> TestCaseResult {
        if let Ok(decoded) = crate::decode(input) {
            let input_len = strip_prefix(input).len() / 2;
            prop_assert_eq!(decoded.len(), input_len);
        }

        Ok(())
    }

    fn mk_expected(bytes: &[u8]) -> String {
        let mut s = String::with_capacity(bytes.len() * 2);

```

--------------------------------

### const-hex Buffer API

Source: https://docs.rs/const-hex/latest/const_hex/struct

This section details the Buffer struct and its associated methods for formatting byte slices into hexadecimal strings.

```APIDOC
## Struct Buffer<const N: usize, const PREFIX: bool = false>

### Description
A correctly sized stack allocation for the formatted bytes to be written into.
`N` is the amount of bytes of the input, while `PREFIX` specifies whether the “0x” prefix is prepended to the output.
Note that this buffer will contain only the prefix, if specified, and null (‘\0’) bytes before any formatting is done.

### Examples
```rust
let mut buffer = const_hex::Buffer::<4>::new();
let printed = buffer.format(b"1234");
assert_eq!(printed, "31323334");
```

## Implementations

### impl<const N: usize, const PREFIX: bool> Buffer<N, PREFIX>

#### `pub const LEN: usize`

The length of the buffer in bytes.

#### `pub const fn new() -> Self`

This is a cheap operation; you don’t need to worry about reusing buffers for efficiency.

#### `pub const fn const_format(self, array: &[u8; N]) -> Self`

Print an array of bytes into this buffer.

#### `pub const fn const_format_upper(self, array: &[u8; N]) -> Self`

Print an array of bytes into this buffer.

#### `pub fn format(&mut self, array: &[u8; N]) -> &mut str`

Print an array of bytes into this buffer and return a reference to its _lower_ hex string representation within the buffer.

#### `pub fn format_upper(&mut self, array: &[u8; N]) -> &mut str`

Print an array of bytes into this buffer and return a reference to its _upper_ hex string representation within the buffer.

#### `pub fn format_slice<T: AsRef<[u8]>>(&mut self, slice: T) -> &mut str`

Print a slice of bytes into this buffer and return a reference to its _lower_ hex string representation within the buffer.

##### Panics
If the slice is not exactly `N` bytes long.

#### `pub fn format_slice_upper<T: AsRef<[u8]>>(&mut self, slice: T) -> &mut str`

Print a slice of bytes into this buffer and return a reference to its _upper_ hex string representation within the buffer.

##### Panics
If the slice is not exactly `N` bytes long.

#### `pub fn to_string(&self) -> String`

Available on **crate feature`alloc`** only.
Copies `self` into a new owned `String`.

#### `pub const fn as_str(&self) -> &str`

Returns a reference to the underlying bytes casted to a string slice.

#### `pub fn as_mut_str(&mut self) -> &mut str`

Returns a mutable reference to the underlying bytes casted to a string slice.

#### `pub fn to_vec(&self) -> Vec<u8>`

Available on **crate feature`alloc`** only.
Copies `self` into a new `Vec`.

#### `pub const fn as_byte_array<const LEN: usize>(&self) -> &[u8; LEN]`

Returns a reference the underlying stack-allocated byte array.

##### Panics
If `LEN` does not equal `Self::LEN`.
This is panic is evaluated at compile-time if the `nightly` feature is enabled, as inline `const` blocks are currently unstable.
See Rust tracking issue #76001.

#### `pub fn as_mut_byte_array<const LEN: usize>(&mut self) -> &mut [u8; LEN]`

Returns a mutable reference the underlying stack-allocated byte array.

##### Panics
If `LEN` does not equal `Self::LEN`.
See `as_byte_array` for more information.

#### `pub const fn as_bytes(&self) -> &[u8]`

Returns a reference to the underlying bytes.

#### `pub unsafe fn as_mut_bytes(&mut self) -> &mut [u8]`

Returns a mutable reference to the underlying bytes.

##### Safety
The caller must ensure that the content of the slice is valid UTF-8 before the borrow ends and the underlying `str` is used.
Use of a `str` whose contents are not valid UTF-8 is undefined behavior.

#### `pub unsafe fn buffer(&mut self) -> &mut [u8]`

Returns a mutable reference to the underlying buffer, excluding the prefix.

##### Safety
See `as_mut_bytes`.

#### `pub const fn as_ptr(&self) -> *const u8`

Returns a raw pointer to the buffer.
The caller must ensure that the buffer outlives the pointer this function returns, or else it will end up pointing to garbage.

#### `pub fn as_mut_ptr(&mut self) -> *mut u8`

Returns an unsafe mutable pointer to the slice’s buffer.
The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.

### Trait Implementations

#### `impl<const N: usize, const PREFIX: bool> AsRef<str> for Buffer<N, PREFIX>`

##### `fn as_ref(&self) -> &str`

Converts this type into a shared reference of the (usually inferred) input type.

#### `impl<const N: usize, const PREFIX: bool> Clone for Buffer<N, PREFIX>`

##### `fn clone(&self) -> Buffer<N, PREFIX>`

Returns a duplicate of the value. Read more
1.0.0 · Source

##### `fn clone_from(&mut self, source: &Self)`

Performs copy-assignment from `source`. Read more

#### `impl<const N: usize, const PREFIX: bool> Debug for Buffer<N, PREFIX>`
```

--------------------------------

### Implement Debug for FromHexError

Source: https://docs.rs/const-hex/latest/const_hex/enum

Shows the implementation of the `Debug` trait for `FromHexError`, enabling formatted output for debugging purposes.

```rust
impl Debug for FromHexError
Source
#### fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
Formats the value using the given formatter. Read more
Source
```

--------------------------------

### Rust: Create uninitialized array

Source: https://docs.rs/const-hex/latest/src/const_hex/impl_core

Provides a const function `uninit_array` to create an array of `MaybeUninit<T>` of a specified size `N`. It leverages `MaybeUninit::uninit().assume_init()` for safety.

```rust
/// `MaybeUninit::uninit_array`
#[inline]
pub(crate) const fn uninit_array<T, const N: usize>() -> [MaybeUninit<T>; N] {
    // SAFETY: An uninitialized `[MaybeUninit<_>; N]` is valid.
    unsafe { MaybeUninit::<[MaybeUninit<T>; N]>::uninit().assume_init() }
```

--------------------------------

### Rust: Serde Integration for Hexadecimal Data

Source: https://docs.rs/const-hex/latest/const_hex/all

Provides Serde serialization and deserialization capabilities for hexadecimal data. This allows seamless integration with data formats that use hexadecimal representations for binary data, simplifying data interchange.

```Rust
mod serde {
    fn deserialize<'de, T>(deserializer: D) -> Result<T, <T as FromHex>::Error>;
    fn serialize<T: ToHex, S>(value: &T, serializer: S) -> Result<S::Ok, S::Error>;
    fn serialize_upper<T: ToHex, S>(value: &T, serializer: S) -> Result<S::Ok, S::Error>;
}
```

--------------------------------

### Rust: Hex Encoding with `serde` (Uppercase Serialization)

Source: https://docs.rs/const-hex/latest/const_hex/index

Handles uppercase hexadecimal encoding for types being serialized with `serde`. This provides an alternative output format for `serde` integration.

```Rust
pub fn serialize_upper<T: ?Sized + ToHex>(value: &T) -> impl serde::Serialize;

```

--------------------------------

### Buffer Conversion and Access Methods (Rust)

Source: https://docs.rs/const-hex/latest/const_hex/struct

Provides methods for converting the buffer's content to a `String` (`to_string`), accessing it as a string slice (`as_str`, `as_mut_str`), and retrieving the underlying byte arrays (`as_byte_array`, `as_mut_byte_array`).

```Rust
pub fn to_string(&self) -> String

pub const fn as_str(&self) -> &str

pub fn as_mut_str(&mut self) -> &mut str

pub fn to_vec(&self) -> Vec<u8>

pub const fn as_byte_array<const LEN: usize>(&self) -> &[u8; LEN]

pub fn as_mut_byte_array<const LEN: usize>(&mut self) -> &mut [u8; LEN]
```

--------------------------------

### Test Hex Buffer Formatting in Rust

Source: https://docs.rs/const-hex/latest/src/const_hex/lib

Tests the `Buffer` struct's ability to format byte slices into hexadecimal strings, both with and without a '0x' prefix. It verifies string lengths, content, and equivalence with expected outputs, also testing decoding functions.

```Rust
fn test_buffer<const N: usize, const LEN: usize>(bytes: &[u8]) -> TestCaseResult {
        if let Ok(bytes) = <&[u8; N]>::try_from(bytes) {
            let mut buffer = Buffer::<N, false>::new();
            let string = buffer.format(bytes).to_string();
            prop_assert_eq!(string.len(), bytes.len() * 2);
            prop_assert_eq!(string.as_bytes(), buffer.as_byte_array::<LEN>());
            prop_assert_eq!(string.as_str(), buffer.as_str());
            prop_assert_eq!(string.as_str(), mk_expected(bytes));

            let mut buffer = Buffer::<N, true>::new();
            let prefixed = buffer.format(bytes).to_string();
            prop_assert_eq!(prefixed.len(), 2 + bytes.len() * 2);
            prop_assert_eq!(prefixed.as_str(), buffer.as_str());
            prop_assert_eq!(prefixed.as_str(), format!("0x{string}"));

            prop_assert_eq!(decode_to_array(&string), Ok(*bytes));
            prop_assert_eq!(decode_to_array(&prefixed), Ok(*bytes));
            prop_assert_eq!(const_decode_to_array(string.as_bytes()), Ok(*bytes));
            prop_assert_eq!(const_decode_to_array(prefixed.as_bytes()), Ok(*bytes));
        }

        Ok(())
    }
```

--------------------------------

### Implement Blanket Trait: VZip

Source: https://docs.rs/const-hex/latest/const_hex/enum

Details the blanket implementation of the `VZip` trait, used for zipping multiple lanes of data together.

```rust
impl<V, T> VZip<V> for T
where V: MultiLane<T>,
Source
#### fn vzip(self) -> V
```

--------------------------------

### Buffer Pointer and Slice Access (Rust)

Source: https://docs.rs/const-hex/latest/const_hex/struct

Includes methods for obtaining raw pointers (`as_ptr`, `as_mut_ptr`) and direct mutable access to the underlying byte buffer (`buffer`) for advanced manipulation.

```Rust
pub const fn as_ptr(&self) -> *const u8

pub fn as_mut_ptr(&mut self) -> *mut u8

pub unsafe fn buffer(&mut self) -> &mut [u8]
```

--------------------------------

### Implement Clone for FromHexError

Source: https://docs.rs/const-hex/latest/const_hex/enum

Demonstrates the implementation of the `Clone` trait for the `FromHexError` enum. This allows `FromHexError` instances to be duplicated.

```rust
impl Clone for FromHexError
Source
#### fn clone(&self) -> FromHexError
Returns a duplicate of the value. Read more
1.0.0 · Source
#### fn clone_from(&mut self, source: &Self)
Performs copy-assignment from `source`. Read more
Source
```

--------------------------------

### Implement Blanket Trait: TryFrom

Source: https://docs.rs/const-hex/latest/const_hex/enum

Illustrates the blanket implementation of the `TryFrom` trait, enabling fallible conversions from type `U` to `T`.

```rust
impl<T, U> TryFrom<U> for T
where U: Into<T>,
Source
#### type Error = Infallible
The type returned in the event of a conversion error.
Source
#### fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
Performs the conversion.
Source
```

--------------------------------

### Rust: Hex Decoding with `serde` (Deserialization)

Source: https://docs.rs/const-hex/latest/const_hex/index

Handles hexadecimal decoding for types being deserialized using the `serde` framework. This enables `serde` to parse hex strings into target types.

```Rust
pub fn deserialize<'de, T: FromHex<T> + Deserialize<'de>>(deserializer: &'de D) -> Result<T, D::Error>;

```

--------------------------------

### TryFrom Type Conversion

Source: https://docs.rs/const-hex/latest/const_hex/struct

Implements `TryFrom` for types `T` from `U`, where `U` implements `Into<T>`. The `try_from` method attempts the conversion, returning a `Result` which is `Ok(T)` on success or an `Err` containing an `Infallible` error type on failure.

```rust
type Error = Infallible
```

```rust
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
```

--------------------------------

### Rust: Hex Encoding with `fmt` Traits

Source: https://docs.rs/const-hex/latest/const_hex/index

Provides a value that can be formatted using the standard Rust `fmt` traits, likely for displaying hex representations.

```Rust
pub fn display<'a, T: ToHex + ?Sized>(value: &'a T) -> impl fmt::Display + 'a;

```

--------------------------------

### TryInto Type Conversion

Source: https://docs.rs/const-hex/latest/const_hex/struct

Implements `TryInto` for types `T` to `U`, where `U` implements `TryFrom<T>`. The `try_into` method attempts the conversion, returning a `Result` with the conversion error type defined by `U`'s `TryFrom` implementation.

```rust
type Error = <U as TryFrom<T>>::Error
```

```rust
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
```

--------------------------------

### Implement Error for FromHexError

Source: https://docs.rs/const-hex/latest/const_hex/enum

Details the implementation of the standard `Error` trait for `FromHexError`, providing methods like `source` and deprecated methods like `description` and `cause`.

```rust
impl Error for FromHexError
1.30.0 · Source
#### fn source(&self) -> Option<&(dyn Error + 'static)>
Returns the lower-level source of this error, if any. Read more
1.0.0 · Source
#### fn description(&self) -> &str
👎Deprecated since 1.42.0: use the Display impl or to_string()
Read more
1.0.0 · Source
#### fn cause(&self) -> Option<&dyn Error>
👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting
Source
#### fn provide<'a>(&'a self, request: &mut Request<'a>)
🔬This is a nightly-only experimental API. (`error_generic_member_access`)
Provides type-based access to context intended for error reports. Read more
Source
```

--------------------------------

### Rust Trait and Implementations for Output Buffering

Source: https://docs.rs/const-hex/latest/src/const_hex/output

Defines an internal `Output` trait in Rust for abstracting over different output buffer types. It includes methods for writing bytes and checking remaining capacity. Implementations are provided for mutable byte slices (`&mut [u8]`) and mutable formatters (`&mut fmt::Formatter<'_>`). The byte slice implementation directly copies data and updates the slice, while the formatter implementation handles writing strings and individual characters, with debug assertions for UTF-8 validity.

```Rust
use core::fmt::{self, Write};

/// Internal trait for abstracting over output buffer types.
pub(crate) trait Output {
    fn write(&mut self, bytes: &[u8]);

    #[inline]
    fn write_byte(&mut self, byte: u8) {
        self.write(&[byte])
    }

    #[inline]
    fn remaining(&self) -> Option<usize> {
        None
    }
}

impl Output for &mut [u8] {
    #[inline]
    fn write(&mut self, bytes: &[u8]) {
        let src = bytes.as_ptr();
        let dst = self.as_mut_ptr();
        let count = bytes.len();
        debug_assert!(self.len() >= count);
        unsafe {
            dst.copy_from_nonoverlapping(src, count);
            *self = core::slice::from_raw_parts_mut(dst.add(count), self.len() - count);
        }
    }

    #[inline]
    fn remaining(&self) -> Option<usize> {
        Some(self.len())
    }
}

impl Output for &mut fmt::Formatter<'_> {
    #[inline]
    fn write(&mut self, bytes: &[u8]) {
        if cfg!(debug_assertions) {
            core::str::from_utf8(bytes).unwrap();
        }
        let _ = self.write_str(unsafe { core::str::from_utf8_unchecked(bytes) });
    }

    #[inline]
    fn write_byte(&mut self, byte: u8) {
        let _ = self.write_char(byte as char);
    }
}
```

--------------------------------

### Implement Blanket Trait: ToString

Source: https://docs.rs/const-hex/latest/const_hex/enum

Details the blanket implementation of the `ToString` trait, allowing conversion of types that implement `Display` into `String` objects.

```rust
impl<T> ToString for T
where T: Display + ?Sized,
Source
#### fn to_string(&self) -> String
Converts the given value to a `String`. Read more
Source
```

--------------------------------

### Hex Serialization and Deserialization Functions

Source: https://docs.rs/const-hex/latest/const_hex/serde/index

Provides functions for serializing raw bytes into hex strings (both lowercase and uppercase) and deserializing hex strings back into raw bytes using the `const-hex` crate.

```rust
# Deserializes a hex string into raw bytes.
fn deserialize(hex_string: &str) -> Result<Vec<u8>, Error> { ... }

# Serializes `data` as hex string using lowercase characters.
fn serialize(data: &[u8]) -> String { ... }

# Serializes `data` as hex string using uppercase characters.
fn serialize_upper(data: &[u8]) -> String { ... }

```

--------------------------------

### Serde Serialization with const-hex (Lowercase)

Source: https://docs.rs/const-hex/latest/src/const_hex/serde

Serializes a byte slice into a lowercase hex string using Serde. The output string is prefixed and its length is twice the input data's length.

```rust
/// Serializes `data` as hex string using lowercase characters.
///
/// Lowercase characters are used (e.g. `f9b4ca`). The resulting string's length
/// is always even, each byte in data is always encoded using two hex digits.
/// Thus, the resulting string contains exactly twice as many bytes as the input
/// data.
#[inline]
pub fn serialize<S, T>(data: T, serializer: S) -> Result<S::Ok, S::Error>
where
    S: Serializer,
    T: AsRef<[u8]>,
{
    serializer.serialize_str(&crate::encode_prefixed(data.as_ref()))
}
```

--------------------------------

### Implement Blanket Trait: Any

Source: https://docs.rs/const-hex/latest/const_hex/enum

Shows the blanket implementation of the `Any` trait for any type `T`, allowing runtime type identification.

```rust
impl<T> Any for T
where T: 'static + ?Sized,
Source
#### fn type_id(&self) -> TypeId
Gets the `TypeId` of `self`. Read more
Source
```

--------------------------------

### Implement Blanket Trait: From

Source: https://docs.rs/const-hex/latest/const_hex/enum

Demonstrates the blanket implementation of the `From` trait, allowing conversion from a type `T` to itself.

```rust
impl<T> From<T> for T
Source
#### fn from(t: T) -> T
Returns the argument unchanged.
Source
```

--------------------------------

### Rust: Initialize array from MaybeUninit array

Source: https://docs.rs/const-hex/latest/src/const_hex/impl_core

Provides an unsafe function `array_assume_init` to convert an array of `MaybeUninit<T>` into an array of `T`. It relies on the caller ensuring all elements are initialized and uses `transpose` for safe conversion.

```rust
/// `MaybeUninit::array_assume_init`
#[inline]
pub(crate) unsafe fn array_assume_init<T, const N: usize>(array: [MaybeUninit<T>; N]) -> [T; N] {
    // SAFETY:
    // * The caller guarantees that all elements of the array are initialized
    // * `MaybeUninit<T>` and T are guaranteed to have the same layout
    // * `MaybeUninit` does not drop, so there are no double-frees
    // And thus the conversion is safe
    unsafe { transpose(array).assume_init() }
```

--------------------------------

### Rust: FromHex and ToHex Traits

Source: https://docs.rs/const-hex/latest/const_hex/all

Introduces traits for converting between byte slices and hexadecimal string representations. The `FromHex` trait facilitates decoding, while the `ToHex` trait handles encoding. These traits are fundamental for integrating with other parts of the library.

```Rust
trait FromHex {
    type Error;
    fn from_hex(hex: &str) -> Result<Self, Self::Error>;
}
trait ToHex {
    fn to_hex(&self) -> String;
    fn to_hex_bytes(&self) -> Vec<u8>;
}
```
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