macro_rules! throw_validation_failure {
($where:expr, { $( $what_fmt:expr ),+ } $( expected { $( $expected_fmt:expr ),+ } )?) => { ... };
}
macro_rules! throw_validation_failure {
($where:expr, { $( $what_fmt:expr ),+ } $( expected { $( $expected_fmt:expr ),+ } )?) => { ... };
}