As mentioned earlier, C++ does not provide more than the bare necessities in terms of libraries. In this book, we will, therefore, have to rely on external libraries where necessary. The most commonly used library in the world of C++ is probably the Boost library (http://www.boost.org). In order to keep the number of used libraries low, we will use the Boost library for hardware-dependent optimizations such as SIMD and GPU.
Throughout this book, we will use the Boost library where the standard C++ library is not enough. Many upcoming parts of the C++ standard are available today in Boost (filesystem, any, optional, and variant), and we will not avoid any libraries planned for inclusion in the C++ standard. We will only use the header-only parts of the Boost library, which means that using them yourself does not require any specific build setup; rather, you just have to include the specified header file.