**NOTE**: This library is an **internal** crate of the [Slint project](https://slint.dev). This crate should **not be used directly** by applications using Slint. You should use the `slint` crate instead. **WARNING**: This crate does not follow the semver convention for versioning and can only be used with `version = "=x.y.z"` in Cargo.toml. The purpose of this crate is to select the default backend for [Slint](https://slint.dev) The backend can either be a runtime or a build time decision. The runtime decision is decided by the `SLINT_BACKEND` environment variable. The built time default depends on the platform. In order for the crate to be available at runtime, they need to be added as feature