## Rust version compatibility
SNAFU is tested and compatible back to Rust 1.18, released on
2017-06-08. Compatibility is controlled by Cargo feature flags.
### Default
- Targets the current stable version of Rust at the time of
release of the crate. Check the Cargo.toml for the exact
version.
### No features - supports Rust 1.18
- Implements [`Error`](std::error::Error) and [`Display`](std::fmt::Display).
- Creates context selectors.
### `rust_1_30` - supports Rust 1.30
- Adds an implementation for [`Error::source`](std::error::Error::source).
- Adds support for re-exporting the `Snafu` macro directly from
the `snafu` crate.