[ruby-core:115146] [Ruby master Misc#19971] Confusing arity of a Proc with implicit rest parameter

Issue #19971 has been reported by andrykonchin (Andrew Konchin). ---------------------------------------- Misc #19971: Confusing arity of a Proc with implicit rest parameter https://bugs.ruby-lang.org/issues/19971 * Author: andrykonchin (Andrew Konchin) * Status: Open * Priority: Normal ---------------------------------------- I've noticed that such proc `proc { |a,| }` has arity `1` that means 1 required parameter, but behaves like there is a rest parameter (`proc { |a, *| }`) that has arity `-2` (that means 1 required parameter + rest parameter). So I am wondering whether it's intentional behaviour and what the rational is behind it. -- https://bugs.ruby-lang.org/