variable destructuring; array to variables list; destructuring assign.

StringManip.d

module StringManip;

import std.range : empty, popFront, front;


auto destr(Arg0, Args...)(ref Arg0 arg0, ref Args args) 
{
    return DestrInstance!(Arg0, Args.length+1)(arg0, args);
}


private struct DestrInstance(T, size_t N)
{
    this(Args...)(ref T arg0, ref Args args)
    {
        items[0] = &arg0;
        foreach(i, ref arg; args) {
            items[i+1] = &arg;
        }
    }

    // overloading assignment operator
    void opAssign(rhs_t)(rhs_t rhs)
    {
        for (size_t i = 0; !rhs.empty && i < N; rhs.popFront(), ++i) {
            *items[i] = rhs.front;
        }
    }

    T* [N] items;
}


nothrow unittest {
    string a, b, c;
    destr(a,b,c) = ["foo1","foo2","foo3","foo4"];
    assert([a,b,c] == ["foo1", "foo2", "foo3"]);

    destr(a,b,c) = ["bar1","bar2"];
    assert([a,b,c] == ["bar1", "bar2", "foo3"]);
}

• Compare with the same C++ implementation: https://gist.github.com/valmat/455d9f9c56237b87f7e2
• run this code: https://run.dlang.io/is/472Dq2

I have written an other implementation that also can retrieve variables for iterable types and tuples:
https://gist.github.com/valmat/763c72465d7a1737229ae1c91393d629