ryu

From a security perspective, ryu is exemplary. It's a pure algorithmic implementation with zero dependencies, meaning your supply chain risk is minimal. The crate does exactly one thing: converts floats to strings using the Ryu algorithm. No network calls, no file I/O, no unsafe behavior that could cause memory corruption in typical usage.

The API is dead simple - you're typically using it indirectly through serde_json or directly via `Buffer::new().format(value)`. There's no input validation needed because it accepts primitive float types directly from Rust's type system. Error handling is essentially non-existent because the operation is infallible for valid floats. This simplicity is a security win: no error messages that could leak information, no edge cases with exceptions.

The library follows secure-by-default principles perfectly because there's nothing to configure wrong. It just works deterministically. The maintainer has shown excellent CVE response historically (though there have been none for this crate), and the code is straightforward enough to audit in an afternoon. For float serialization in security-sensitive contexts, this is as safe as it gets.

Ryu is refreshingly straightforward to use in practice. The API is minimalist in the best way—just import and call the formatting functions. No configuration structs, no builder patterns, no lifetime wrangling. You get Buffer::new() for stack allocation or direct formatting via macros, and it just works. The type signatures are dead simple, making IDE autocompletion trivial.

What really stands out is how it drops into existing codebases. Replacing standard library formatting with ryu is typically a one-line change, and the performance gains are immediate and measurable. Error handling is non-existent because the operations are infallible—no Result types to unwrap, which simplifies calling code considerably.

Documentation is lean but complete. The README covers the 95% use case in seconds, and rustdoc explains the few API surfaces clearly. No surprises, no gotchas. The crate follows Rust conventions perfectly, so if you know Rust, you know ryu. It's the kind of library that you add once and never think about again.

Ryu is refreshingly straightforward to use. The API is minimal—basically just import the `Buffer` type and call `format()` or `format_finite()`. There's essentially zero learning curve if you've ever converted a float to a string before. The documentation is sparse but that's because there's genuinely not much to explain. You get exactly what you need: fast float formatting with correct rounding.

In practice, integration is painless. I've used it in both performance-critical serialization code and general-purpose formatting. Error handling is non-existent because the operations are infallible (you're just formatting numbers). The only gotcha is remembering to use the buffer for stack allocation when performance matters, but even if you forget and use the convenience methods, it still works fine.

Debugging is trivial since there's almost no surface area for things to go wrong. The output matches Rust's standard formatting, so there are no surprises. Common use cases like JSON serialization or CSV export are completely straightforward—just swap your `to_string()` calls with ryu and enjoy the speedup.