On 2012-03-07 00:19, H. S. Teoh wrote:
On Tue, Mar 06, 2012 at 11:40:19PM +0100, Artur Skawina wrote:
On 03/06/12 20:37, H. S. Teoh wrote:
On Tue, Mar 06, 2012 at 01:51:51AM +0100, Artur Skawina wrote:
[...]
class A {
string prop1;
int prop2;
void serialize(this THIS)() {
__serialize(cast(THIS*)&this);
}
}
void __serialize(T)(T* obj) {
writef("%s {\n", typeid(*obj));
foreach (name; __traits(allMembers, T)) {
static if (__traits(compiles,&__traits(getMember,obj,name))) {
alias typeof(__traits(getMember,obj,name)) MT;
static if (is(MT==function))
continue;
else {
auto m = __traits(getMember,obj,name);
if (is(MT:const(char[])))
writef(" %s %s = \"%s\";\n", typeid(MT), name, m);
else
writef(" %s %s = %s;\n", typeid(MT), name, m);
}
}
}
writef("}\n");
}
And it will do the right thing for derived classes too.
[...]
Hmm, it only does the right thing for derived class if invoked with the
derived class pointer. It doesn't work (and in retrospect can't possibly
work, since "this THIS" is a compile-time parameter) if you only have
the base class pointer.
Of course. But is it really necessary to fully serialize derived classes
*w/o* knowing what they are? In that case deserialization will probably be
"interesting" too...
It's easy. We already output the class name in the serialization, so to
deserialize, we just call Object.factory(class_name), then a per-class
deserialize() method similar to the above that reconstructs class data.
That only works for classes with no constructor, or a default
constructor, which sucks. It's fairly easy to implement your own version
that does not call constructors.
What I needed was for serialize() to be polymorphic at runtime, so it
does have to be overloaded in every derived class. Hmph... looks like I
can't avoid using mixins. :-(
If you can "register" the classes to be serialized then typeid() can
help the __serialize() implementation...
True. But TypeInfo doesn't let you access actual data members without
using void* casts and pointer arithmetic, whereas compile-time
introspection does.
There are ways around that, have a look in my serialization library
Orange: https://github.com/jacob-carlborg/orange
--
/Jacob Carlborg
