Updated.

2 Lines Of Code and 3 C++17 Features - The overload Pattern

by Bartlomiej Filipek

From the article:

While I was doing research for my book and blog posts about C++17 several times I stumbled upon this pattern for visitation of std::variant:

template<class... Ts> struct overload : Ts... { using Ts::operator()...; };
template<class... Ts> overload(Ts...) -> overload<Ts...>;

With the above pattern, you can provide separate lambdas “in-place” for visitation.

It’s just two lines of compact C++ code, but it packs a few interesting concepts.

Let’s see how this thing works and go through the three new C++17 features that make this patter possible...