On Wednesday, 7 September 2016 at 11:20:18 UTC, Lodovico Giaretta
wrote:
I guess the only thing you can ask and obtain here (I mean,
with a bug report) is that @disable this() should be allowed to
coexist with static opCall(). That would prevent your users
from instantiating structs the wrong way (both nested in other
structs and on the stack).
Or perhaps explicit this() could be allowed if we have `@disable
S init` defined for S:
S s; // error, S.init is disabled
S s = S(); // OK
So how would this deal with Walter's 4 axioms:
1. So S.init is a valid initializer
No, S.init is disallowed. Any code that needs it should fail to
compile.
2. So all instances of S can be guaranteed to contain a valid
instance
Yes, because the only instances that exist are those explicitly
constructed by constructor call.
3. So default initialization is guaranteed to succeed
No, this is disallowed (see 1).
4. So any struct constructor starts with a valid state
This can be handled by initializing fields to their respective
.init values before any constructor of S is called.
