> struct A {
>    void opAssign(int v) const {}
> }
> 
> struct B {
>     enum a = A();
>     alias a this;
> }
> 
> enum BB = B();
> 
> void main() {
>     BB = 10; // Deprecation: Cannot use alias this to partially initialize variable B() of type B. Use a.opAssign
> }

If you change `enum a = A()` to `immutable a = A()`, the deprecation disappears.

On Friday, 13 November 2020 at 10:08:47 UTC, Jack Applegame wrote:
>> struct A {
>>    void opAssign(int v) const {}
>> }
>> 
>> struct B {
>>     enum a = A();
>>     alias a this;
>> }
>> 
>> enum BB = B();
>> 
>> void main() {
>>     BB = 10; // Deprecation: Cannot use alias this to partially initialize variable B() of type B. Use a.opAssign
>> }
>
> If you change `enum a = A()` to `immutable a = A()`, the deprecation disappears.

But if you change `enum a = A()` to `static immutable a = A()`, the deprecation remains.