Godot: func _process(_delta) should be default preset instead of func _process(delta)

[golddotasksquestions]

Godot version:
3.1 stable

Issue description:
func _process(delta) results in a warning, func _process() is not possible
Hence func _process(_delta) should be the default preset.

When a new user adds a default script to a node the first time, they should not get a warning.

[isaacremnant]

I disagree, variables shouldn't be "ignored" by default and I think it's the user's job to choose to put the underscore when desired.

[akien-mga]

I disagree too.

The proper solution IMO is what I proposed in https://github.com/godotengine/godot/issues/27576#issuecomment-478745395 i.e. split this warning into two warnings:

• One for user-defined methods (ON by default), so my_method(arg_i_wont_use) will raise a warning
• One for engine callbacks (OFF by default), so _process(delta) won't raise a warning unless you enabled this warning yourself

[golddotasksquestions]

The proper solution IMO is what I proposed in #27576 (comment) i.e. split this warning into two warnings:

One for user-defined methods (ON by default), so my_method(arg_i_wont_use) will raise a warning
One for engine callbacks (OFF by default), so _process(delta) won't raise a warning unless you enabled this warning yourself

Yes, this sounds like a much better solution!