Compilation error due to an unallowed default value in a signature
class X::Parameter::Default does X::Comp { }
Compile-time error thrown when a parameter in a signature has default value, but isn't allowed to have one. That is the case with slurpy parameters (because a slurpy always binds successfully, even to zero arguments) and with mandatory parameters.
Example:
sub f($x! = 3) { }
dies with
===SORRY!=== Cannot put default on required parameter $x
And
sub f(*@ = 3) { }
dies with
===SORRY!=== Cannot put default on anonymous slurpy parameter
Returns a string describing how the parameter is qualified that makes it disallow default values, for example "slurpy" or "mandatory".
Returns the parameter name