Which is already doable from CPAN using Devel::Declare, hence Method::Signatures::Simple, Sub::Curried, MooseX::Method::Signatures etc. The stuff in core is, h

Which is already doable from CPAN using Devel::Declare, hence Method::Signatures::Simple, Sub::Curried, MooseX::Method::Signatures etc. The stuff in core is, however, way, way more elegant than the way Devel::Declare currently does it - which was rather the point, Devel::Declare was "retrofit to existing perl5 VMs what will hopefully be core later".