Associative arrays can't have a static array as key

[Michiel]

I have a template function like this:

void foo(T)(T bar) {
    int[T] bla;
    /* more code */
}

And I occasionally want to call it with a string literal.

foo("test");

But the compiler sais I can't, because "test" is of type char[4], and
apparently associative arrays can't take a static array as key.

This isn't documented. In fact, the documentation says that type[dim] can be
implicitly converted to type[].

But putting that aside for the moment, how can I convince D to automatically
make it a dynamic array, so I can use my function?

Thanks!