3.1.0

• Added: support for constraints like ^2.x-dev and ~2.x-dev, not very useful but seen in the wild and failed to validate with 3.0.1
• Fixed: invalid aliases will no longer throw, unless explicitly validated by Composer in the root package

3.0.1

• Fixed: handling of some invalid -dev versions which were seen as valid

1.6.0

• Added: support for constraints like ^2.x-dev and ~2.x-dev, not very useful but seen in the wild and failed to validate with 1.5.2
• Fixed: invalid aliases will no longer throw, unless explicitly validated by Composer in the root package

1.5.2

• Fixed: handling of some invalid -dev versions which were seen as valid
• Fixed: some doctypes

3.0.0

• Break: Renamed EmptyConstraint, replace it with MatchAllConstraint
• Break: Unlikely to affect anyone but strictly speaking a breaking change, *.* and such variants will not match all dev-* versions anymore, only * does
• Break: ConstraintInterface is now considered internal/private and not meant to be implemented by third parties anymore
• Added Intervals class to check if a constraint is a subsets of another one, and allow compacting complex MultiConstraints into simpler ones
• Added CompilingMatcher class to speed up constraint matching against simple Constraint instances
• Added MatchAllConstraint and MatchNoneConstraint which match everything and nothing
• Added more advanced optimization of contiguous constraints inside MultiConstraint
• Added tentative support for PHP 8
• Fixed ConstraintInterface::matches to be commutative in all cases

2.0.0

• Break: dev-master, dev-trunk and dev-default now normalize to dev-master, dev-trunk and dev-default instead of 9999999-dev in 1.x
• Break: Removed the deprecated AbstractConstraint
• Added getUpperBound and getLowerBound to ConstraintInterface. They return Composer\Semver\Constraint\Bound instances
• Added MultiConstraint::create to create the most-optimal form of ConstraintInterface from an array of constraint strings

1.5.1

• Fixed: Parsing of aliased version was not validating the alias to be a valid version

1.5.0

• Added: some support for date versions (e.g. 201903) in ~ operator
• Fixed: support for stabilities in ~ operator was inconsistent

1.4.2

• Fixed: collapsing of complex constraints lead to buggy constraints

1.4.1

• Changed: branch-like requirements no longer strip build metadata - composer/semver#38.