Crate kstring

Key String: Optimized for map keys.

Examples

String creation

// Explicit
let literal = kstring::KString::from_static("literal");
// Implicit
let literal = kstring::KString::from("literal");

// Explicit
let inline = kstring::KString::try_inline("stack").unwrap();
let inline = kstring::KString::from_ref("stack");

let formatted: kstring::KStringCow = format!("Hello {} and {}", literal, inline).into();

Background

Considerations:

• Large maps
• Most keys live and drop without being used in any other way
• Most keys are relatively small (single to double digit bytes)
• Keys are immutable
• Allow zero-cost abstractions between structs and maps (e.g. no allocating when dealing with struct field names)

Ramifications:

• Inline small strings rather than going to the heap.
• Preserve &'static str across strings (KString), references (KStringRef), and lifetime abstractions (KStringCow) to avoid allocating for struct field names.
• Use Box<str> rather than String to use less memory.

Feature Flags

• std (enabled by default) — Allow use of std
• arc — O(1) clone support
• max_inline — Inline (stack) strings use the full width of KStrings
• unsafe (enabled by default) — Allow unsafe code
• serde — serde compatibility

Modules

• backend

Structs

• KStringBase
  A UTF-8 encoded, immutable string.
• KStringCowBase
  A reference to a UTF-8 encoded, immutable string.
• KStringRef
  A reference to a UTF-8 encoded, immutable string.
• StackString
  Fixed-size stack-allocated string

Type Aliases

• KString
  A UTF-8 encoded, immutable string.
• KStringCow
  A reference to a UTF-8 encoded, immutable string.