20211023; version 1.431:
  * Fixed a bug that caused /[^;]*^;?/ not to match the beginning of
    "abc" when the multiline flag is not set.

20211003; version 1.430:
  * Bug fix: When the Boyer-Moore-Horspool search was performed, NIRE
    did not update the lastIndex member of the regexp class.
  * Merged partially the code provided by Marko Njezic. (Thanks!)
  * Modified the compiler to unroll a repetition if the length of the
    unrolled expression is relatively short, instead of using the
    counter. E.g., /(?:\d+\.){2,3}/ -> /\d\.\d\.(?:\d\.)?/.

20210919; version 1.420:
  * Added a new optimisation for the quantifier '?' (I.e., {0,1}).
  * Changed the version number of the ECMAScript specification
    referenced in misc/conftest.cpp to 2021.
  * Changed the parameter type of operator[](), index(), and endIndex()
    in re_match class from unsigned int to size_t, to prevent an
    ambiguous overload resolution.
  * Modified u32ctou8c() in misc/conftest.cpp for Visual Studio 2017 not
    to throw std::length_error.
  * Modified exec(), test() in regexp class to use a newly added member
    variable of the re_match type instead of creating a local variable
    when a reference to an instance of the re_match type is not passed
    to these functions as an argument.
  * Fixed some inconsistencies that can occur between the default mode
    and a debugging mode in which an optimisation is turned off by
    defining a NIREDBG_* macro.
    * Thanks to Marko Njezic for the reports about the last four issues
      along with the sample code for performance improvement, which has
      not been merged yet into NIRE.

20210429; version 1.412:
  * Fixed another bug in the optimisation introduced in version 1.400,
    which caused /aa|a|aa/ not to match "a".

20210424; version 1.411:
  * Fixed a bug in the optimisation introduced in version 1.400, which
    caused /abc|ab|ac/ not to match "ac".

20210407; version 1.410:
  * Fixed a memory leak in move assignment operators used by the pattern
    compiler since 1.400.

20210214; version 1.400:
  * Added a new optimisation for alternatives that consist of string
    literals, such as /abc|abd|acde/.
  * Minor improvements.

20210131; version 1.310:
  * Improved internal UTF-8 iterators.

20200724; version 1.300:
  * Added code to prevent redundant save and restore operations when
    nested capturing round brackets are processed.
  * Introduced the Eytzinger layout for binary search in the character
    class.
  * Reimplemented linear search for small character classes.
  * Modified handling of the property data used for parsing the name for
    a named capturing group. Now they are loaded only when needed
    instead of loading into an instance of basic_regex.

20200703; version 1.220:
  * Fixed a bug that could cause a valid UTF-8 sequence being adjacent
    to an invalid UTF-8 sequence to be skipped when the BMH algorithm
    was used (inherited from SRELL).

20200630; version 1.210:
  * Refined Boyer-Moore-Horspool search.

20200628; version 1.200:
  * Optimisation adjustments.

20200620; version 1.101:
  * Move the group name validity check to after parsing the \u escape.
  * Updated misc/conftest.cpp to version 1.001. Changed the version
    number of the ECMAScript specification referenced by to 2020 (ES11).

20200616; version 1.100:
  * Modified to perform code unit by code unit matching when string
    literals are compared case-sensively. This change can benefit search
    in UTF-8 or UTF-16.

20200601; version 1.000:
    The first released version.