Use .get() in MultiD Assoc Array?

[Philippe Sigaud]

On Thu, Aug 30, 2012 at 7:18 PM, Paul <phshaffer at gmail.com> wrote:
> From the book a way to respond to a non-existent key in an assoc. array:
>
> assert(aa["hello"] == "ciao");
> // Key "hello" exists, therefore ignore the second argume
> assert(aa.get("hello", "salute") == "ciao");
> // Key "yo" doesn’t exist, return the second argument
> assert(aa.get("yo", "buongiorno") == "buongiorno");
>
> Should this work in multidimensional arrays?
>
> aa.get("key1" "key2" "key2", "nonexistent") == "sometext"

D multi-key associative arrays do not exist as such, they are
associative arrays inside one another. When you write

int[string][string][double] aa;

you can use get() on aa, but only on its keys, which are of type
double, whereas its values are of type int[string][string].

I guess an effect similar to what you're asking can be obtained by
using a tuple as a key:

import std.typecons;
int[Tuple!(string,string,double)] aa;

auto p = aa.get(tuple("abc","def", 3.14), 0);  // 0 is the default value.