it-works/iterators/README.md

counted
=======

```c++
for(auto x : counted(v)) {
	... x.value ... x.index ...
}
```
`x.value` is a reference to the element in the container (so you can change it's value), `x.index` is what it is.
Container should have forward iterators.


This headers is purely a handy tool for the range-based-for-loops (ie `for(auto x : counter(v))`). Using it explicitly with iterators is not recommended!


There is no const version of it. Doing `for(const auto x : counted(v))` doesn't make it impossible to change `x` (so the element in the container can be modified).


Example:

```c++
for(auto x : counted(v)) {
	std::cout << "v[" << x.index << "] = " << x.value << std::endl;
	x.value *= 2;
}
```
This will output the container `v`, with it's indeces. And it will multiply every value in `v` by 2.