Nathan created this issue wrt this topic:
And there was also an existing related one:

PRs with tests welcome. :-)

Cheers, Paul.

On Tue, Jan 9, 2018 at 10:09 PM, Алексей Афанасьев <> wrote:
It would be great to rework signatures of DGM with wildcards. It should fix a lot of stupid compile errors with @ComileStatic and will definitely improve Groovy support in IDE's. 

Alexey Afanasiev.

2017-12-27 15:28 GMT+03:00 Jochen Theodorou <>:
On 27.12.2017 03:11, Nathan Harvey wrote:
A few methods in DefaultGroovyMethods don't utilize wildcards, for example,
the Map plus operator:

public static <K, V> Map<K, V> plus(Map<K, V> left, Map<K, V> right) { ... }

Which causes a compile error on the following, for example:

Map<String, Object> map = [:]
map + [hello: 'world']

A few other methods might suffer from this problem. Does anyone have
anything against changing them to support wildcards? eg: plus(Map<K, V>
left, Map<? extends K, ? extends V> right)

spontaneously I would say you are right... The problem with generics is that they always require 2-3 steps extra, you tend to not to see right away. So I assume this has been very much overlooked

bye Jochen