Macro sp_runtime::impl_tx_ext_default

macro_rules! impl_tx_ext_default {
    ($call:ty ; , $( $rest:tt )*) => { ... };
    ($call:ty ; validate $( $rest:tt )*) => { ... };
    ($call:ty ; prepare $( $rest:tt )*) => { ... };
    ($call:ty ; weight $( $rest:tt )*) => { ... };
    ($call:ty ;) => { ... };
}

Helper macro to be used in a impl TransactionExtension block to add default implementations of weight, validate, prepare or any combinations of the them.

The macro is to be used with 2 parameters, separated by “;”:

• the Call type;
• the functions for which a default implementation should be generated, separated by “ “; available options are weight, validate and prepare.

Example usage:

impl TransactionExtension<FirstCall> for EmptyExtension {
	type Val = ();
	type Pre = ();

	impl_tx_ext_default!(FirstCall; weight validate prepare);
}

impl TransactionExtension<SecondCall> for SimpleExtension {
	type Val = u32;
	type Pre = ();

	fn weight(&self, _: &SecondCall) -> Weight {
		Weight::zero()
	}

	fn validate(
			&self,
			_origin: <T as Config>::RuntimeOrigin,
			_call: &SecondCall,
			_info: &DispatchInfoOf<SecondCall>,
			_len: usize,
			_self_implicit: Self::Implicit,
			_inherited_implication: &impl Encode,
		) -> ValidateResult<Self::Val, SecondCall> {
		Ok((Default::default(), 42u32, origin))
	}

	impl_tx_ext_default!(SecondCall; prepare);
}