spire_enum_macros 0.2.1

Procedural macros to facilitate enum usage, such as when delegating implementations, extracting variant types, or creating enum tables.
Documentation 
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use super::*;

macro_rules! bail {
	($span:expr => $msg:expr $(,$span_extra:expr => $msg_extra:expr)* $(,)?) => {{
		#[allow(unused_mut)]
		let mut err = Error::new($span.span(), $msg);
		$( err.combine(Error::new($span_extra.span(), $msg_extra)); )*
		return Err(err)
	}};
}

macro_rules! err_expected_only_one {
	($span1:expr, $span2:expr) => {{
		let err = {
			let mut _temp = Error::new($span1.span(), "expected only one, first occurrence here");
			_temp.combine(Error::new($span2.span(), "second occurrence here"));
			_temp
		};

		return Err(err);
	}};
}

macro_rules! assign_unique_or_panic {
	($maybe_first:expr, $second:expr) => {
		if let _Some(first) = $maybe_first {
			err_expected_only_one!(first, $second);
		} else {
			$maybe_first = _Some($second);
		}
	};
}

pub(crate) use assign_unique_or_panic;
pub(crate) use bail;
pub(crate) use err_expected_only_one;