How to declare array with auto

Question

I have been playing with auto and I noticed that for most cases you can replace a variable definition with auto and then assign the type.

I

Answer 1

Not exactly the same thing, and it's a bit ugly, but it is possible to deduce the element type from a list initializer and declare the array directly, as follows:

template
struct array_trait
{
    using element_type = T;
    array_trait(T(&&)[]);
};

decltype(array_trait({4,5,7}))::element_type a[] = {4,5,7};

std::cout << typeid(a).name() << std::endl;

for (unsigned i = 0; i < 3; i++)
    std::cout << a[i] << std::endl;

The type should be int[3] and the output should be 4 5 7.