Structured Binding Declarations

Do you often work with tuples or pairs?

If not, then you should probably start looking into those handy types. Tuples enable you to bundle data ad-hoc with excellent library support instead of creating small custom types. The language features like structured binding make the code even more expressive and concise.

Consider a function that returns two results in a pair:

std::pair<int, bool> InsertElement(int el) { ... }

You can write:

auto ret = InsertElement(...)

And then refer to ret.first or ret.second. However, referring to values as .first or .second is also not expressive - you can easily confuse the names, and it’s hard to read. Alternatively, you can leverage std::tie which will unpack the tuple/pair into local variables:

int index { 0 };
bool flag { false };
std::tie(index, flag) = InsertElement(10);

Such code might be useful when you work with std::set::insert which returns std::pair: