The original idea is that there should be *no such thing* as
default construction of a struct as being anything other than
T.init. The default construction of a struct should be a
compile time creature, not a runtime one.
Any methods or workarounds to try and make T() produce
something different from T.init is bad D practice. The compiler
tries to statically head them off, but probably should do a
better job of that.
The only reason to associate no parameter constructors with
default values is because of how C++ works. There is no reason why
Foo foo; (1)
should be equivalent to
auto foo = Foo(); (2)
in D. We could allow constructors with no parameters and make (1)
equivalent to
auto foo = Foo.init; (3)
The current workaround when one wants (2) to construct the object
at runtime is to define a static opCall, but that's messy and
inconsistent. It's just one more quirk one needs to learn to
effectively use the language.
