Structured Bindings (C++17)

Structured bindings unpack a pair, a tuple, an array, or the public members of a struct into individually named variables in a single declaration. Before C++17, getting at the pieces of a std::pair meant typing .first and .second everywhere, and iterating a std::map meant writing it->first and it->second. This chapter covers the syntax, the three categories of types the standard supports, the reference-binding modes, the common cases like map iteration and multi-return functions, the rules for hooking custom types into the feature, and the limits.