applies a function to all elements of the list
None
A list of the "mapped" items is returned.
If any item ist mapped to an error object than the result ist not a collection but the first (left-to-right-order) error object created.
| std::map_or_error | applies a function to all items of a collection |
| std::reduce | computes a kind of sum from the items of a collection |
| std::map_reduce | combines a map and a reduce operation into a single operation |