Crate rocstr

RocStr

Overview

Rust OuiCloud Str

An immutable fixed capacity stack based generic copy string.

The RocStr is a string backed by a fixed size array.

It keeps track of its length, and is parameterized by SIZE for the maximum capacity.

SIZE is of type usize but is range limited to u32::MAX; attempting to create RocStr with larger capacity will panic.

Usage

Basic usage

cargo install rocstr

#[derive(Copy, Clone)]
pub struct Customer {
    id: u32,
    first_name: RocStr<64>,
    last_name: RocStr<64>,
}

let alice = Customer {id: 1, first_name: "Alice".into(), last_name: "Adams".into()};
let bob = Customer {id: 2, first_name: "Bob".into(), last_name: "Bennett".into()};

let alice_name = alice.first_name + " " + alice.last_name;
let bob_name = bob.first_name + " " + bob.last_name;

assert_eq!(alice_name, "Alice Adams");
assert_eq!(bob_name, "Bob Bennett");

Motivation

Yet another copy string type for Rust.

But, this one is particularly shaped to ease async programming :

• it is owned which means no lifetime management, unlike Rust standard &str
• it implements Copy trait, unlike Rust standard String, which means fast and implicit copy
• it exposed an immutable API, no interior mutability, which means thread safety

More over, it was designed to cover web full stack programming range, from full featured back-end server to WASM front-end.

Library	owned	impl Copy	immut. API	no std	no unsafe	Note
core::str	❌	❌	❌	✅	➖	core immutable string
std::String	✅	❌	❌	❌	➖	std string
imstr::ImString	✅	❌	❌	❌	❌	use Arc<String> under the hood
smol_str::SmolStr	✅	❌	❌	✅	❌	rust-analyzer string
bytestring::ByteString	✅	❌	❌	✅	❌	actix string
flexstr::FlexStr	✅	❌	❌	✅	❌
copstr::Str	✅	✅	❌	❌	❌
copystr::sXX	✅	✅	❌	❌	✅	old impl before const generic
arraystring::ArrayString	✅	✅	❌	✅	❌	old impl before const generic
tinystr::TinyAsciiStr	✅	✅	❌	✅	❌	ascii only
arrayvec::ArrayString	✅	✅	❌	✅	❌	unfortunately, it uses unsafe
rocstr::RocStr	✅	✅	✅	✅	✅	this crate

Use cases

The target use case is web full stack programming :

• mapping database strings with bound size (char(SIZE), varchar(SIZE), etc…)
• easing async functional programming (owned, impl Copy, immutability)

Supported Rust Versions

The current MSRV is 1.60.

Safety

This crate uses #![forbid(unsafe_code)] to ensure everything is implemented in 100% Safe Rust.

Crate Features

RocStr is built with these features enabled by default:

• std enables functionality dependent on the std lib

Optionally, the following dependencies can be enabled:

• serde enables serde Serialize/Deserialize support
• postgres enables PostgreSql type support

RocStr supports no_std mode (enabled via default-features = false)

License

RocStr is distributed under the terms of both the MIT license and the Apache License (Version 2.0).

See LICENSE-APACHE and LICENSE-MIT, and COPYRIGHT for details.

Re-exports

pub use crate::rocerr::InsufficientCapacity;

pub use crate::rocstr::RocStr;

Modules

postgres

Postgres type implementation

rocerr

RocStr errors type : insufficient capacity error type used with try_... functions

rocstr

An immutable fixed capacity stack based generic copy string.

serialize

Serde Serialize and Deserialize implementation