core-foundation-rs
Compatibility
By default it targets macOS 10.7.
To enable features added in macOS 10.8, set Cargo feature mac_os_10_8_features. To have both 10.8 features and 10.7 compatibility, also set mac_os_10_7_support. Setting both requires weak linkage, which is is a nighty-only feature as of Rust 1.19.