uniq and array of enum members (That are all strings)

[bauss via Digitalmars-d-learn]

Is there a way to achieve the following:

import std.stdio;

import std.algorithm : uniq;
import std.array : array;

enum Foo : string
{
    a = "aa",
    b = "bb",
    c = "cc"
}

void main()
{
    auto a = [Foo.a, Foo.b, Foo.a, Foo.b, Foo.c];

    auto b = a.uniq;

    writeln(b);
    // Expected output: [a, b, c]
    // Outputs: [a, b, a, b, c]
}