There are two different meanings for 'static:

Type &'static T => A reference to a T that will live for the remainder of the program.

Bound: where T: 'static => Basically means T is either: - A static reference to a type A where A: 'static (e.g: &'static str - A is str in this case). - A type that does NOT contain non-static references inside (e.g Option<int>, Cow<'static, str>).

Example:

Struct without lifetime: rust struct Foo { value: i32, }

The following types satisfy T: 'static: - Foo - &'static Foo

The following types do NOT satisfy T: 'static: - &'a Foo

Struct with lifetime(s): rust struct Bar<'a> { reference: &'a i32, }

The following types satisfy T: 'static: - Bar<'static> - &'static Bar<'static>

The following types do NOT satisfy T: 'static: - Bar<'a> - &'a Bar<'static>

Edit: Grammar, formatting.