"What decision should existing library take? rewriting whole library? rewriting critical part ? in these case almost all of developers time should be devoted on

"What decision should existing library take? rewriting whole library? rewriting critical part ? in these case almost all of developers time should be devoted on rewriting existing C++ code." Why on earth would you rewrite existing code just because the language gains new features? Old code is not going to magically decompose - that's one of the benefits of C++ - you can continue to use the old battletested codebases while utilizing the nice features of C++11 and onwards. "p.s. one of my friends in college used to joke about C++. He calls C++ : "feature adding contest"." Adding the capability to utilize more degrees of freedom into a system does not mean one is compulsed to use all of those. One of the pitfalls of C++ is that people imagine they must write "idiomatic" C++ - which they understand is that they must use every language feature available. Which is idiotic. The only good C++ is pragmatic C++ - which depends on the problem one is going to solve.