Issue #19259 has been updated by nobu (Nobuyoshi Nakada). https://github.com/ruby/ruby/pull/7031 ---------------------------------------- Bug #19259: `Data#with` doesn't call `initialize` nor `initialize_copy` https://bugs.ruby-lang.org/issues/19259#change-100815 * Author: ko1 (Koichi Sasada) * Status: Open * Priority: Normal * Backport: 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN ---------------------------------------- `Data#with` doesn't call `initialize` nor `initialize_copy`. It is confirmation request. ```ruby class P < Data.define(:x, :y) def initialize_copy(...) p :initialize_copy super end def initialize(...) p :initialize super end end pt = P.new(1, 2) #=> :initialize pt.clone #=> :initialize_copy pt.dup #=> :initialize_copy pt.with(x: 10) #=> N/A ``` For example, if an author of `P` add validation code, `#with` skips it. -- https://bugs.ruby-lang.org/