In my last post, "Parallel Algorithms of the STL with the GCC Compiler", I presented the necessary theory about the C++17 algorithm. Today, I made a performance test using the Microsoft and GCC compiler to answer the simple question: Does the execution policy pay off?

GCC supports my favorite C++17 feature: the Standard Template Library (STL) parallel algorithms. I recognized this a few days ago, and I'm happy to write a post about it and share my enthusiasm.

C++11 has eight associative containers. With C++17, you can more comfortably insert new elements into them, merge existing associative containers, or move elements from one container into another if they are similar. But that is not all. The access to the associative and sequential containers was unified.

The idea is quite simple. The Standard Template (STL) has more than 100 algorithms for searching, counting, and manipulating ranges and their elements. With C++17, 69 are overloaded, and a few new ones are added. The overloaded and new algorithm can be invoked with a so-called execution policy. By using the execution policy, you can specify whether the algorithm should run sequentially, parallel, or parallel and vectorized.

What have std::optional, std::any, and std::variant in common? You can construct them in place. But that is not everything. A std::variant supports a visitor.

The purpose of std::string_view is to avoid copying data already owned by someone else and of which only a non-mutating view is required. So, this post is mainly about performance.

My post, C++17 - What's New in the Library, was fine for the first overview. Today, I will look deeper into the new library. 

After I provided the big picture of the new C++17 core language in my post "C++17 - What's New in the Core Language", I will give you more details today. The details are mainly about inline variables, templates, automatic type deduction with auto, and attributes.

What's new in the library? A lot. To make the long story short. We get a std::string_view, parallel algorithm of the Standard Template Library, a file system library, and the three new data types std::any, std::optional, and std::variant. Let's look at the details.

C++11, C++14, and C++17. I guess you see the pattern.  Later this year, we will get a new C++ standard. In March 2017, the C++17 specification reached the Draft International Standard stage. Before I dive into the details, I will give you an overview of C++17.