void main() @nogc

{

    import std.container, std.stdio;

    auto a = Array!string("Test1", "Test2", "Test3", "Test1", "Test2");

    import std.algorithm, std.range;

    auto r = a[].enumerate.filter!(t => t[1] == "Test2").map!(t => t[0]);

    debug r.writeln;

}