Merge pull request fffaraz#199 from ChaoMai/master

add ck in Concurrency category.

Author: fffaraz

README.md

@@ -170,6 +170,7 @@ A curated list of awesome C/C++ frameworks, libraries, resources, and shiny thin
 * [ArrayFire](https://github.com/arrayfire/arrayfire) - A general purpose GPU library. [BSD]
 * [Boost.Compute](https://github.com/boostorg/compute) - A C++ GPU Computing Library for OpenCL. [Boost]
 * [Bolt](https://github.com/HSA-Libraries/Bolt) - A C++ template library optimized for GPUs. [Apache2]
+* [ck](https://github.com/concurrencykit/ck) - Concurrency primitives, safe memory reclamation mechanisms and non-blocking data structures. [BSD]
 * [C++React](https://github.com/schlangster/cpp.react) - A reactive programming library for C++11. [Boost]
 * [Intel TBB](https://www.threadingbuildingblocks.org/) - Intel® Threading Building Blocks. [GPL2 with runtime exception]
 * [junction](https://github.com/preshing/junction) - A library of concurrent data structures in C++. [BSD]