Does structured binding work with std::vector?

Question

Is it possible to use structured binding with vectors?

E.g.

std::vector vec{1, 2, 3};
auto [a, b, c] = vec;

Above code u

Answer 1

It's easy enough to create a basic wrapper over your vector that gives access to it like a tuple. Since there is indeed no way to retrieve a vector's size at compile time, this throws std::out_of_range if you attempt to destructure too short a vector. Unfortunately I don't know of a way to deduce the number of requested bindings, so that's explicit.

Full code:

#include 
#include 
#include 

template 
struct vector_binder {
    std::vector &vec;

    template 
    T &get() {
        return vec.at(I);
    }
};

namespace std {
    template
    struct tuple_size>
    : std::integral_constant { };

    template
    struct tuple_element> { using type = T; };
}

template 
auto dissect(std::vector &vec) {
    return vector_binder{vec};
}

int main() {
    std::vector v{1, 2, 3};
    auto [a, b] = dissect<2>(v);

    a = 5;
    std::cout << v[0] << '\n'; // Has changed v through a as expected.
}

Rvalue and const versions of vector_binder as well as better names are left as an exercise to the reader :)

See it live on Coliru