| //! Key String: Optimized for map keys. |
| //! |
| //! # Examples |
| //! |
| //! String creation |
| //! ```rust |
| //! // 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 |
| //! |
| #![cfg_attr(feature = "document-features", doc = document_features::document_features!())] |
| #![cfg_attr(feature = "safe", forbid(unsafe_code))] |
| |
| #[cfg(not(feature = "std"))] |
| compile_error!("`std` feature is required; reserved for future `no_std` support"); |
| |
| mod stack; |
| mod string; |
| mod string_cow; |
| mod string_ref; |
| |
| pub mod backend; |
| |
| pub use stack::StackString; |
| pub use string::*; |
| pub use string_cow::*; |
| pub use string_ref::*; |
| |
| #[cfg(test)] |
| mod test { |
| #[test] |
| fn test_size() { |
| println!( |
| "String: {}", |
| std::mem::size_of::<crate::string::StdString>() |
| ); |
| println!( |
| "Box<str>: {}", |
| std::mem::size_of::<crate::backend::DefaultStr>() |
| ); |
| println!( |
| "Box<Box<str>>: {}", |
| std::mem::size_of::<Box<crate::backend::DefaultStr>>() |
| ); |
| println!("str: {}", std::mem::size_of::<&'static str>()); |
| println!( |
| "Cow: {}", |
| std::mem::size_of::<std::borrow::Cow<'static, str>>() |
| ); |
| } |
| } |