map4<R extends Object> method

TResolvableOption<Object> map4<R extends Object>(
  1. R mapper(
    1. T
    )
)

Implementation

@pragma('vm:prefer-inline')
TResolvableOption<Object> map4<R extends Object>(R Function(T) mapper) {
  return map((e) => e.map3((e) => mapper(e as T))).reduce();
}