Trevor Hickey Trevor Hickey - 9 days ago 5
C++ Question

How can I emulate destructuring in C++?

In JavaScript ES6, there is a language feature known as destructuring. It exists across many other languages as well.

In JavaScript ES6, it looks like this:

var animal = {
species: 'dog',
weight: 23,
sound: 'woof'
}

//Destructuring
var {species, sound} = animal

//The dog says woof!
console.log('The ' + species + ' says ' + sound + '!')


What can I do in C++ to get a similar syntax and emulate this kind of functionality?

Answer

For the specific case of std::tuple (or std::pair) objects, C++ offers the std::tie function which looks similar:

std::tuple<int, bool, double> my_obj {1, false, 2.0};
// later on...
int x;
bool y;
double z;
std::tie(x, y, z) = my_obj;
// or, if we don't want all the contents:
std::tie(std::ignore, y, std::ignore) = my_obj;

I am not aware of an approach to the notation exactly as you present it.