Ruby 2.4.0 Released

We are pleased to announce the release of Ruby 2.4.0.

Ruby 2.4.0 is the first stable release of the Ruby 2.4 series. It introduces many new features, for example:

Introduce hash table improvement (by Vladimir Makarov)

Improve the internal structure of hash table (st_table) by introducing open addressing and an inclusion order array. This improvement has been discussed with many people, especially with Yura Sokolov.

Binding#irb: Start a REPL session similar to binding.pry

While you are debugging, you may often use p to see the value of variables. With pry you can use binding.pry in your application to launch a REPL and run any Ruby code. r56624 introduces binding.irb which behaves like that with irb.

Unify Fixnum and Bignum into Integer

Though ISO/IEC 30170:2012 doesn’t specify details of the Integer class, Ruby had two visible Integer classes: Fixnum and Bignum. Ruby 2.4 unifies them into Integer. All C extensions which touch the Fixnum or Bignum class need to be fixed.

See also the ticket and akr’s slides.

String supports Unicode case mappings

String/Symbol#upcase/downcase/swapcase/capitalize(!) now handle Unicode case mappings instead of only ASCII case mappings.

Performance improvements

Ruby 2.4 also contains the following performance improvements including language changes:

Array#max, Array#min

[x, y].max and [x, y].min are optimized to not create a temporary array under certain conditions.


Added Regexp#match?, which executes a regexp match without creating a back reference object and changing $~ to reduce object allocation.

Other performance improvements


Thread#report_on_exception and Thread.report_on_exception

Ruby ignores exceptions in threads unless another thread explicitly joins them. With report_on_exception = true, you can notice if a thread has died due to an unhandled exception.

Send us feedback what should be the default for report_on_exception and about report-on-GC, which shows a report when a thread is garbage collected without join.

Thread deadlock detection now shows threads with their backtrace and dependency

Ruby has deadlock detection around waiting threads, but its report doesn’t include enough information for debugging. Ruby 2.4’s deadlock detection shows threads with their backtrace and dependent threads.

Other notable changes since 2.3

  • Support OpenSSL 1.1.0 (drop support for 0.9.7 or prior)
  • ext/tk is now removed from stdlib Feature #8539
  • XMLRPC is now removed from stdlib Feature #12160

See NEWS or commit logs for details.

With those changes, 2523 files changed, 289129 insertions(+), 84670 deletions(-) since Ruby 2.3.0!

Merry Christmas, Happy Holidays, and enjoy programming with Ruby 2.4!



    SIZE:   12572424 bytes
    SHA1:   944d2588308391b20a89642472454d1dfe7b2360
    SHA256: 440bbbdc49d08d3650f340dccb35986d9399177ad69a204def56e5d3954600cf
    SHA512: bef7bb53f63fb74073d071cc125fb67b273ed0779ef43c2d2969089b9ca21fff1bd012281c5b748f7a3c24dd26e71730d7248c05a01cb23ab2089eb4d02115fe

    SIZE:   14104044 bytes
    SHA1:   d44a3c50a0e742341ed3033d5db79d865151a4f4
    SHA256: 152fd0bd15a90b4a18213448f485d4b53e9f7662e1508190aa5b702446b29e3d
    SHA512: 21c9f596b42dd9cba7a53963a59fed0c2e0c1eb960a4ac7087ea3eaa991ce9252d32639e1edcb75b1d709bc07c4820a6dc336ab427d0643c6e6498e0eacdbc8b

    SIZE:   9906880 bytes
    SHA1:   038804bbd0e77508dd2510b729a9f3b325489b2e
    SHA256: 3a87fef45cba48b9322236be60c455c13fd4220184ce7287600361319bb63690
    SHA512: 975a5388592adc038461e0acebb6c0efee242891b2ea8621476401458efe2bc0fdd317d3bf99beb745b0b3808410efdff33862da29c95c027f457943721e3ab6

    SIZE:   15758757 bytes
    SHA1:   29e1bab11551011718c35a51827edcb55bd656fc
    SHA256: 5c2bbfa26fd6a15a2d70961874b0f3a386206fcc5f698e240dd8b0c9f0f18c5e
    SHA512: 31d932372ce490eeac0a70bc8dcf842909a90435422398d069c05cf01d994936064b8f4e60879e28a8655c1296eb8e180e348cb95e001ed6ca73cda0ff77de23