use std::fill to populate vector with increasing numbers

Question

I would like to fill a vector using std::fill, but instead of one value, the vector should contain numbers in increasing order after.

Answer 1

There is another option - without using iota. For_each + lambda expression can be used:

vector ivec(10); // the vector of size 10
int i = 0;            // incrementor
for_each(ivec.begin(), ivec.end(), [&](int& item) { ++i; item += i;});

Two important things why it's working:

1. Lambda captures outer scope [&] which means that i will be available inside expression
2. item passed as a reference, therefore, it is mutable inside the vector