API model

The library is written in Rust, and Rust programs use it directly. Every other language uses bindings generated from a single description of the API, so C, C++, .NET and Java get the same features and the same documentation, each in the style of that language.

One model, every language

We describe each class, interface, struct and function of the API, with its documentation, once in a model. Our code generator, oo_bindgen, turns that model into the code for each language:

Because everything comes from the same model, a feature reaches every language in the same release, and the bindings can't drift apart. Our blog post explains the approach in more depth.

What runs in your application

Whatever language you use, every call ends up in the same Rust code, so a client or a server behaves the same in every language. Only the thin layer that you call is different:

Terms used in this guide

The guide describes the API with general terms. This is what each one is in your language; the language pages have the details. The Rust API is ordinary Rust rather than generated, so its column shows the closest equivalent.

Term	C	C++	Java	.NET	Rust
Class	Opaque pointer	Move-only class	Class	Class	Struct
Interface	Function pointers	Abstract class	Interface	Interface	Trait
Struct	Struct	Struct	Class	Class	Struct
Iterator	Iterator	Iterator	List<T>	ICollection<T>	Iterator
Async method	Callback	Callback	CompletionStage<T>	Task<T>	async fn
Error	Error code	Exception	Exception	Exception	Result

In C and C++, an iterator is valid only inside the callback that receives it. Java and .NET copy the values into a collection that you can keep.