## C++20

The final meeting for new features in C++ is over, so let’s explore the new features in C++, from a data science point of view. This is the largest release of C++ since C++11, and when you consider C++14 and C++17 to be interim releases, the entire 9 year cycle is possibly the largest yet! It may not feel quite as massive as C++11, since we didn’t have interim releases for C++11 and because C++11 is a much more complete, useful language than C++03, but this is still a really impactful release!

Let’s look at the major new features, as well as collections of smaller ones.

## C++17

The every-three-year cycle has changed the development of C++; we are now getting consistent releases somewhere in-between the major and minor releases of old. The 2017 release may be called minor by some, with a huge portion of the planned improvements being pushed back another 3-6 years, but there were several substantial changes in useful areas; it is much more impactful than C++14, for example. This almost feels like a lead-in release to C++20.

The std::variant, std::optional, and std::any additions to the standard library are huge, and can restructure the way you program (and are available for older C++ releases through Boost and other libraries).

## C++14

Unlike C++11, this is a minor release, focused mostly on improvements on top of C++11 changes, with very little that one could call “new”. C++14 feels a little more natural than C++11 by expanding the usage of features and implementing common sense additions that were missed in the original C++11 release. There were also quite a few bug fixes; several of these were backported into C++11 mode in compilers.

Also, while C++11 is always available in ROOT 6, C++14 requires a flag and compatible compiler, so C++14 features are often unavailable. The Conda-Forge ROOT package has C++17 enabled.