Invalid type argument usage

Reports type variables used as arguments in locations that their variance does not allow, so long as they are not marked as unchecked. A type variable may have a variance of either covariant (out), contravariant (in), or invariant (neither out nor in).

The following rules are used to check the type arguments used in attribute and method declarations:

unchecked type arguments are ignored.
Covariant type arguments may only be used in locations that produce values (for example, return types and block parameters).
Contravariant type arguments may only be used in locations that consume arguments (for example, parameters and block return types).
Invariant type arguments may be used in both locations that produce values and consume arguments.

Example:

class Example[in A, out B]
  # Covariant type variable 'B' of class 'Example' used in a contravariant position, ...
  def call: (B) -> A
end

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

RbsInvalidTypeArgumentUsage

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | RBS | Probable bugs

Inspection ID: RbsInvalidTypeArgumentUsage

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection RbsInvalidTypeArgumentUsage

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

RubyMine 2025.2

Inspection Details
By default bundled with:	Qodana for Ruby 2025.2, RubyMine 2025.2,

Last modified: 18 September 2025