A knob for controlling the match semantics of a packed multiple string
searcher.
This differs from the MatchKind type in the top-level
crate module in that it doesn’t support “standard” match semantics,
and instead only supports leftmost-first or leftmost-longest. Namely,
“standard” semantics cannot be easily supported by packed searchers.
For more information on the distinction between leftmost-first and
leftmost-longest, see the docs on the top-level MatchKind type.
Unlike the top-level MatchKind type, the default match semantics for this
type are leftmost-first.
Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.
Use leftmost-first match semantics, which reports leftmost matches.
When there are multiple possible leftmost matches, the match
corresponding to the pattern that appeared earlier when constructing
the automaton is reported.