Ruby Issue Tracking System

10/29/2026

09:00 AM Ruby Revision c0813055 (git): Track the given members of Data#initialize without copying them

Data#initialize copied the member list on every call to find the missing
keywords, then cleared the given ones. A byte per member is enough to
track what was given, and the member list is only needed to build the
error message, so look i... shia (Sangyong Sim)

01:20 AM Ruby Revision d176801d (git): Cache Struct members only on the owner Ractor

struct_ivar_get caches a member list found on a superclass into the
subclass with rb_ivar_set. The ID has no "@", so it skips the Ractor
ownership check, and a Ractor that does not own the class ends up
writing class fields concurrently ... shia (Sangyong Sim)

10/28/2026

01:01 PM Ruby Feature #22437: Speed up creation and basic operations of Struct / Data

3rd PR is here. [Track the given members of Data#initialize without copying them](https://github.com/ruby/ruby/pull/19581)
Before digging into where to store the members, I'm going to look into the ISEQ approach first. shia (Sangyong Sim)

10/22/2026

02:24 PM Ruby Revision 8ff4ae13 (git): Store the members directly in Data.new with positional arguments

Data.new turned positional arguments into a keyword Hash and called
initialize with it. When initialize is the default Data#initialize and
every member is given, that call can only store the members and freeze
the instance, so do that di... shia (Sangyong Sim)

01:21 PM Ruby Feature #22437: Speed up creation and basic operations of Struct / Data

2nd pr is here. [Store the members directly in Data.new with positional arguments](https://github.com/ruby/ruby/pull/19481) shia (Sangyong Sim)

12:38 PM Ruby Feature #22437: Speed up creation and basic operations of Struct / Data

Eregon, Thanks for your comments. I would like to go that way too if possible. But as you said, generating ISEQs needs a careful look at whether the code stays maintainable, and at other side effects. So for now, I will keep working on t... shia (Sangyong Sim)

10/19/2026

11:13 AM Ruby Revision f90d381d (git): Read the member count from self in Struct#initialize

struct_alloc() sizes an instance by the member count of its class, so the
instance's own length can be used instead of looking the hidden
__members__ ivar up on the class again.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anth... shia (Sangyong Sim)

10:36 AM Ruby Feature #22437: Speed up creation and basic operations of Struct / Data

First pr is here. [Read the member count from self in Struct#initialize](https://github.com/ruby/ruby/pull/19417) shia (Sangyong Sim)

10/14/2026

01:05 PM Ruby Feature #22437 (Open): Speed up creation and basic operations of Struct / Data

## Summary
Struct and Data are slower to create and to operate on than a hand-written class that does the same job.
Struct / Data are usually chosen because people expect them to be lightweight value objects, yet once they sit on a h... shia (Sangyong Sim)

09/05/2026

12:08 AM Ruby Bug #22292 (Closed): YJIT/ZJIT: Struct accessor crashes after an instance variable is set on a Struct that exactly fills the largest GC slot

ruby -v: ruby 4.0.6 (2026-07-14 revision 03b6d3f889) +PRISM [x86_64-linux]
Also reproduced on 4.0.1 and on master (3600d410ad, 2026-09-04). Not reproduced on 3.4.9.
## Summary
With YJIT or ZJIT enabled, this sequence crashes the p... shia (Sangyong Sim)