> 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.