Assigning to array of structs with custom constructor

[cc]

```d
struct Foo {
	string s;
	this(string s) { this.s = s; }
}
Foo foo = "a";
Foo[] foos = ["a"]; // Error: cannot implicitly convert 
expression `["a"]` of type `string[]` to `Foo[]`
Foo[] foos = cast(Foo[]) ["a"]; // Error: e2ir: cannot cast `"a"` 
of type `string` to type `Foo`
```

Was there a way to do this?  I thought I recalled seeing 
something like this before, but I can't seem to find it.