c++ - C++展现了什么？

Question

C++具有std::accumulate:

std::accumulate performs a left fold. In order to perform a right fold, one must reverse the order of the arguments to the binary operator, and use reverse iterators.

Kwang's Haskell Blog -- unfold and fold

unfoldr builds a list from a seed value while foldr reduces a list to a summary value.

C++的“展开”是什么？

Answer 1

std::iota 。

Fills the range [first, last) with sequentially increasing values, starting with value and repetitively evaluating ++value.

std::generate / std::generate_n 。

Assigns each element in range [first, last) a value generated by the given function object g.

Assigns values, generated by given function object g, to the first count elements in the range beginning at first, if count>0. Does nothing otherwise.