C++17

• Boost filesystem
• execution policy: parallel algorithm support for range-based for loops - potential for easily parallelsing existing code
• structured bindings
• clamp
• std::optional
• [[maybe_unused]]

C++20

• spaceship operator
• range based for loops with initialiser
• bit header
• coroutines
• ranges and views - a nod to strongly typed, const languages like Haskell
• https://en.cppreference.com/w/cpp/utility/source_location
• https://en.cppreference.com/w/cpp/numeric/constants

Wish list

See the compiler support matrix.

• std::format
• modules - wait for clang12, gcc11

Modules

Look interesting but not available until clang-12.

• https://www.bfilipek.com/2018/11/parallel-alg-perf.html
• https://gcc.gnu.org/wiki/cxx-modules
• https://clang.llvm.org/docs/Modules.html
• https://vector-of-bool.github.io/2019/03/10/modules-1.html
• https://en.cppreference.com/w/cpp/language/modules