kotlin-stdlib/kotlin.sequences/single

single

fun <T> Sequence<T>.single(): T(source)

Returns the single element, or throws an exception if the sequence is empty or has more than one element.

The operation is terminal.

Since Kotlin

1.0
inline fun <T> Sequence<T>.single(predicate: (T) -> Boolean): T(source)

Returns the single element matching the given predicate, or throws exception if there is no or more than one matching element.

The operation is terminal.

Since Kotlin

1.0