iota

Usage

std::iota fills a range with some incrementable value. The function is almost like Python’s range function, but in C++. You can use it like this:

std::vector<int> my_range(10);
std::atoi(my_range.begin(), my_range.end(), 0);
// Now, `my_range` contains 0, 1, 2, .., 9.

The name std::iota is a bit cryptic. It is the kind of function name that, if used properly, signals you have discovered the zen of C++.

Naming Theory 1

iota means:

an infinitesimal amount

and is also the Greek letter i.

std::iota captures the common pattern using i:

for (int i = 0; i < c.size(); ++i) {
  c[i] = i;
}

Naming Theory 2

std::iota is a reversal of std::atoi. In some sense, these functions are mirror imagaes of each other:

• std::atoi parses an array (of ascii characters) into an integer, (unless there’s an error, in which case std::atoi just returns 0).
• std::iota broadcasts an integer into an array.

Functions like iota and atoi remind me of bash, where we embrace the yin-yang dynamics and karmetic symmetry of the universe with syntax like:

case esac

if fi

do done (od was taken)