pub fn settle<'a>(
constraints: &[(&str, &'a Constraint)],
) -> Result<Option<&'a str>, SettleError>Expand description
Settle every (requester, constraint) on a package: each must hold on the ref it ends at,
whether or not it selects anything. A Constraint::RefPin holds only at that ref, a
Constraint::Semver never at a pin, and Constraint::Latest anywhere. So the package
ends at the one pin if there is one (returned; None means select chooses among the
tags), and two pins, or a pin beside a range, refuse. A Latest beside a pin holds but
drifts: it asked for the newest and gets a fixed ref.