Attribrutes

• An attribute is metadata applied to some module, crate or item

#[attribute = "value"]
#[attribute(key = "value")]
#[attribute(value)]
fn foo() {}

• This metadata can be used to/for

  • conditional compilation of code
  • set crate name, version and type (binary or library)
  • disable lints (warnings)
  • enable compiler features (macros, glob imports, etc.)
  • link to a foreign library
  • mark functions as unit tests
  • mark functions that will be part of a benchmark
  • create custom decorator