Augmented assignment creates a new collection under the hood

Reports augmented assignment (+=) expressions on a read-only Collection.

Augmented assignment (+=) expression on a read-only Collection temporarily allocates a new collection, which may hurt performance.

Change type to mutable quick-fix can be used to amend the code automatically.

Example:

fun test() {
    var list = listOf(0)
    list += 42 // A new list is allocated here, equivalent to list = list + 42
}

After the quick-fix is applied:

fun test() {
    val list = mutableListOf(0)
    list += 42
}

Inspection Details
Available in:	IntelliJ IDEA 2023.3, Qodana for JVM 2023.3
Plugin:	Kotlin, @snapshot@

Last modified: 13 July 2023