Use `entry` instead of deprecated `find_or_insert_with`.
Format the match expression.
Merge pull request #43 from forkloop/master

Use `entry` instead of deprecated `find_or_insert_with`.
Fixed link to documentation
Merge pull request #45 from vhbit/patch-1

Fixed link to documentation
abstract renamed to erase in iron
Merge pull request #46 from amw-zero/fix-abstract

abstract renamed to erase in iron
(fix) Error::erase has been removed
Merge branch 'johnmq-master'