struct MyStruct {
    int x;
}
void main() {
    MyStruct[string] aa1 = ["A": MyStruct(1),
                            "B": MyStruct(2),
                            "C": MyStruct(3)]; // OK
    MyStruct[string] aa2 = ["A": {1}, "B": {2}, "C" : {3}]; // Error
}


DMD 2.064 alpha gives:

test.d(8): Error: not an associative array initializer