Re: Member Access Based On A Runtime String

[Adrian Matoga via Digitalmars-d-learn]

On Tuesday, 1 March 2016 at 05:05:40 UTC, Jack Stouffer wrote:

In Python, I can do this:

    my_obj = Obj()
    string_from_func = func()
    setattr(my_obj, string_from_func, 100)

Say func() returns "member1" or "member2", the setattr would then set either one of those to 100.

Is there any equivalent in D?

struct Foo
{
        string foo = "dog";
        int bar = 42;
        int baz = 31337;
}

void set(P, T)(ref P p, string name, auto ref T value)
{
        foreach (mem; __traits(allMembers, P)) {
                static if (is(typeof(__traits(getMember, p, mem)) Q)) {
                        static if (is(Q : T)) {
                                if (mem == name) {
                                        __traits(getMember, p, mem) = value;
                                        return;
                                }
                        }
                }
        }
        assert(0, P.stringof ~ " has no member " ~ name);
}

unittest
{
        Foo foo;
        foo.set("bar", 15);
        assert(foo.bar == 15);
        foo.set("foo", "cat");
        assert(foo.foo == "cat");
}