Derive Macro fuzzcheck::DefaultMutator

#[derive(DefaultMutator)]
{
    // Attributes available to this derive:
    #[field_mutator]
    #[ignore_variant]
}

Implement a mutator for the type and make it the type’s DefaultMutator.

The mutator will be called <Name>Mutator. It can be constructed in two ways:

1. Through the DefaultMutator trait, for example:

use fuzzcheck::DefaultMutator;

#[derive(Clone, DefaultMutator)]
struct X<A> {
    field: A,
}
let mutator = <X<u8> as DefaultMutator>::default_mutator();
// but it can also be inferred by the rust compiler:
let mutator = X::<u8>::default_mutator();

2. By using <Name>Mutator::new(..) with the submutators for every field given as argument, for example:

use fuzzcheck::DefaultMutator;

#[derive(Clone, DefaultMutator)]
enum Either<A, B> {
    Left(A),
    Right(B)
}
let mutator = EitherMutator::new(u8::default_mutator(), bool::default_mutator());
// mutator impl Mutator<Either<u8, bool>>

Similarly to make_mutator!, you can use the attributes #[field_mutator] and #[ignore_variant] to customise the generated mutator.