Construct an used-defined hash table container type from an AA-literal expression

[Per Nordlöw]

On Sunday, 5 July 2020 at 21:22:13 UTC, ikod wrote:
> struct AA(K,V)
> {
>     void opAssign(V[K] aa)
>     {
>     }
> }
>
> void main()
> {
>     AA!(string, int) custom_aa;
>     custom_aa = ["one":1, "two":2];
> }

Forget to mention that I want the assign call (to `opAssign`) in 
`main` to be non-(GC)heap allocating like when using C++'s 
std::initializer_list.