Struct Compact 

pub struct Compact(/* private fields */);

Available on crate features alloc or std only.

A strategy that aggressively inlines data to minimize heap allocations and memory usage.

Overview

The Compact strategy prioritizes memory efficiency over conversion speed. It automatically converts heap-allocated data back to inline storage whenever possible (when data size ≤62 bytes) after operations like advance(), truncate(), or split_to/off().

This makes Compact ideal when:

• Memory footprint is critical
• You want to minimize heap allocations
• You’re working with small, frequently-modified buffers
• Conversions to Bytes are rare

Behavior

• Inline → Inline: Small data stays inline (≤62 bytes)
• Heap → Inline: Automatically inlines when data shrinks ≤62 bytes
• Smart optimization: Operations like advance(), truncate(), and split_to/off() can trigger heap→inline conversion

Example

use smol_bytes::compact::Bytes;
use bytes::Buf;

// Create heap-allocated bytes (>62 bytes)
let mut data = Bytes::from(vec![1u8; 100]);
assert!(data.is_heap());

// Advance past most data
data.advance(70); // Only 30 bytes remain

// Automatically converted to inline! (Compact strategy saves memory)
assert!(!data.is_heap());

Comparison with Shared

Operation	Compact	Shared
Heap→Inline on shrink	✅ Yes	❌ No
Bytes conversion	📋 May copy	⚡ Zero-copy
Memory usage	💾 Lower	💾 Higher
Best for	Memory efficiency	Speed, Bytes interop

Trait Implementations

impl Clone for Compact

fn clone(&self) -> Compact

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Compact

impl Debug for Compact

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

Formats the value using the given formatter.

impl Eq for Compact

impl Hash for Compact

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Compact

fn cmp(&self, other: &Compact) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for Compact

fn eq(&self, other: &Compact) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for Compact

fn partial_cmp(&self, other: &Compact) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for Compact