This is a *-sys crate; you shouldn't use its API directly. The proj crate is designed for general use.
A guide to the functions can be found here: https://proj.org/development/reference/functions.html. Run cargo doc (optionally --open) to generate the crate documentation.
By default, libproj (via PROJ v7.1.x) must be present on your system. While this crate may be backwards-compatible with older PROJ 7 and PROJ 6 versions, this is neither tested or supported.
Enable these in your Cargo.toml like so:
proj-sys = { version = "0.18.1", features = ["bundled_proj"] }
proj-sys = { version = "0.18.1", features = ["pkg_config"] }
Note that these features are mutually exclusive.
bundled_proj (Linux and macOS targets):
libproj. Note that SQLite3 and libtiff must be present on your system if you wish to use this feature, and that it builds libproj without its native network functionality; you will have to implement your own set of callbacks if you wish to make use of them (see the proj crate for an example).pkg_config (Linux and macOS targets)
pkg-config to add search paths to the build script. Requires pkg-config to be installed (available on Homebrew, Macports, apt etc.)Licensed under either of
at your option.