Issue #15381 has been updated by sanjioh (Fabio Sangiovanni). Eregon (Benoit Daloze) wrote in #note-4:
Should `**` call `to_h` rather than `to_hash`, similar to `*` calling `to_a` and not `to_ary`?
Hi, I’m learning Ruby and the fact that `**` calls `to_hash` rather than `to_h` surprised me; I would expect it to be consistent to `*` calling `to_a`. I suppose that changing this behavior would break to much code, though. A pointer to the decision making process that lead to using `to_hash` would be helpful nonetheless. Thanks! ---------------------------------------- Feature #15381: Let double splat call `to_h` implicitly https://bugs.ruby-lang.org/issues/15381#change-110200 * Author: sawa (Tsuyoshi Sawada) * Status: Open ---------------------------------------- The single splat calls `to_a` implicitly on the object (if it is not an array already) so that, for example, we have the convenience of writing conditions in an array literal: ```ruby a = [ *(:foo if some_condition), *(:bar if another_condition), ] ``` And the ampersand implicitly calls `to_proc` on the object (if it is not a proc already) so that we can substitute a block with an ampersand followed by a symbol: ```ruby some_method(&:some_method_name) ``` Unlike the single splat and ampersand, the double splat does not seem to implicitly call a corresponding method. I propose that the double splat should call `to_h` implicitly on the object if it not already a Hash so that we can, for example, write a condition in a hash literal as follows: ```ruby h = { **({a: 1} if some_condition), **({b: 2) if another_condition), } ``` There may be some other benefits of this feature that I have not noticed yet. -- https://bugs.ruby-lang.org/