C++ got a lot of additions in C++11, C++14, and, most recently, C++17. By now, it is a completely different language compared to what it was just a decade ago. The C++ standard does not only standardize the language, as it needs to be understood by the compilers, but also the C++ standard template library (STL).
This book explains how to put the STL to the best use with a broad range of examples. But at first, this chapter will concentrate on the most important new language features. Mastering them will greatly help you write readable, maintainable, and expressive code a lot.
We will see how to access individual members of pairs, tuples, and structures comfortably with structured bindings and how to limit variable scopes with the new if and switch variable initialization capabilities. The syntactical ambiguities, which were introduced by C++11 with the new bracket initialization syntax, which looks the same for initializer lists, were fixed by new bracket initializer rules. The exact type of template class instances can now be deduced from the actual constructor arguments, and if different specializations of a template class will result in completely different code, this is now easily expressible with constexpr-if. The handling of variadic parameter packs in template functions became much easier in many cases with the new fold expressions. At last, it became more comfortable to define static globally accessible objects in header-only libraries with the new ability to declare inline variables, which was only possible for functions before.
Some of the examples in this chapter might be more interesting for implementers of libraries than for developers who implement applications. While we will have a look at such features for completeness reasons, it is not too critical to understand all the examples of this chapter immediately in order to understand the rest of this book.
