std_types::hash_set/std::map_reduce

combines a map and a reduce operation into a single operation

Parameters

self: the set to work on
map_function: the function to apply to each element of the set
reduce_function (default: append): the function to apply to each member of the set
unit (default: undefined): the value to return for empty sets

None

Does not create an intermediate set to hold the "mapped" values.

combines a map and a reduce operation into a single operation

std::map	applies a function to all items of a collection
std::reduce	computes a kind of sum from the items of a collection