X::Composition::NotComposable Reference
Compilation error due to composing an ineligible type
What it is #
Routines #
Signatures are reproduced from the documentation, including their declared return types. A routine listed here is part of the type's published interface; whether Raku++ implements it is a separate question, answered by the examples below.
method target-name #
method target-name(--> Str:D)Returns Str:D.
Returns the name of the type that should be composed, but failed.
method composer #
method composer(--> Mu)Returns Mu.
Returns the type that should be composed into the target, but which isn't a role.
Examples, run three ways #
Every example below comes from the official documentation, together with the output that documentation asserts. Each was then executed by Rakudo and by Raku++ when this page was built. Where the three agree, one result is shown; where they do not, all three are — because which of them is wrong is exactly the information worth having.
3 no-output
class X::Composition::NotComposable is Exception { }Not executed: the documentation states no expected output for this example.
class B { }
class C does B { }Not executed: the documentation states no expected output for this example.
B is not composable, so C cannot compose it
Not executed: the documentation states no expected output for this example.