void test(S)()
{
    // multi-pattern regex example
    S[] arr = [`([a-z]+):(\d+)`, `(\d+),\d+`];
    auto multi = regex(arr); // multi regex
    S str = "abc:43 12,34";
    auto m = str.matchAll(multi);
    assert(m.front.whichPattern == 1);
    assert(m.front[1] == "abc");
    assert(m.front[2] == "43");
    m.popFront();
    assert(m.front.whichPattern == 2);
    assert(m.front[1] == "12");
}

import std.meta : AliasSeq;
static foreach (C; AliasSeq!(string, wstring, dstring))
    // Test with const array of patterns - see https://issues.dlang.org/show_bug.cgi?id=20301
    static foreach (S; AliasSeq!(C, const C, immutable C))
        test!S();