Macro frunk::field []

macro_rules! field {
    ( ( $ ( $ repeated : ty ) , * ) , $ value : expr ) => { ... };
    (
( $ ( $ repeated : ty , ) * ) , $ value : expr ) => { ... };
    (
$ name_type : ty , $ value : expr ) => { ... };
    (
$ name_type : ty , $ value : expr , $ name : expr ) => { ... };
}

Used for creating a Field

There are 3 forms of this macro:

  • Create an instance of the Field struct with a tuple name type and any given value. The runtime-retrievable static name field will be set to the the concatenation of the types passed in the tuple type used as the first argument.

Examples

let labelled = field![(n,a,m,e), "joe"];
assert_eq!(labelled.name, "name");
assert_eq!(labelled.value, "joe")Run
  • Create an instance of the Field struct with a custom, non-tuple name type and a value. The runtime-retrievable static name field will be set to the stringified version of the type provided.
enum first_name {}
let labelled = field![first_name, "Joe"];
assert_eq!(labelled.name, "first_name");
assert_eq!(labelled.value, "Joe");Run
  • Create an instance of the Field struct with any name type and value, and a custom name, passed as the last argument in the macro
// useful aliasing of our type-level string
type age = (a, g, e);
let labelled = field![age, 30, "Age"];
assert_eq!(labelled.name, "Age");
assert_eq!(labelled.value, 30);Run