Boost C++ Application Development Cookbook - Second Edition

How to do it...

The flat containers are part of the Boost.Container library. We already saw how to use some of its containers in the previous recipes. In this recipe, we'll be using a flat_set associative container:

1. We'll need to include only a single header file:

#include <boost/container/flat_set.hpp>

2. After that, we are free to construct the flat container and experiment with it:

#include <algorithm>#include <cassert>int main() {    boost::container::flat_set<int> set;

3. Reserving space for elements:

    set.reserve(4096);

4. Filling the container:

    for (int i = 0; i < 4000; ++i) {        set.insert(i);    }

5. Now, we can work with it just like with std::set:

    // 5.1    assert(set.lower_bound(500) - set.lower_bound(100) == 400);    // 5.2    set.erase(0); // ...