'filterIsInstance' call with a class literal argument

Reports calls of the Kotlin standard library function filterIsInstance with a class literal argument. It is more idiomatic to use a version of this function with a reified type parameter, to avoid the ::class.java syntax.

Note: inspection is not reported for generic class literals because the Class<*, *> syntax in the type argument list may be undesirable.

Example:

  fun foo(list: List<*>) {
      list.filterIsInstance(Int::class.java)
  }

After the quick-fix is applied:

  fun foo(list: List<*>) {
      list.filterIsInstance<Int>()
  }

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.

FilterIsInstanceCallWithClassLiteralArgument

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 | Kotlin | Style issues

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 FilterIsInstanceCallWithClassLiteralArgument

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

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025