I Wish I Could Use C++ 1x/y/z
C++11, C++14 and C++17 provided a sensible amount of new libraries and language features. However, for some reasons ranging from inertia or even resistance to change, up to complicated customer demands or lack of good compiler support, using those new shiny tools can be out of the question. This tutorial will cover a selection of highly useful C++14/17 idioms and see how you can rebuild them in C++11/14 so you can use them in constrained contexts, or when the language support is there but the library support is not. We will also cover the actual state of popular compilers (GCC, Clang, Visual Studio) to see if they support what they claim to do, so the transition can be smoothed out. A short list of points to be covered are: generic lambdas, if constexpr, tuple and typelist manipulation with integer_sequence, void_t, template-alias tricks, and fold operator emulation. For each of those, we'll introduce the feature, explain what kind of use cases they solve and how to reproduce them with an old compiler or a limited version of the language or standard library. The question will then be, how far back in time can we go for all of these.