Thanks to Pieter Wuille for most of the work on this commit.
I did not fixup the overhaul commit, because a rebase conflicted
with "remove fields of ser_streamplaceholder".
I prefer not to risk making a mistake while resolving it.
The nType and nVersion fields of stream objects are never accessed
from outside the class (or perhaps from the inside too, I haven't checked).
Thus no need to have them in a placeholder, whose only purpose is to
fill the "Stream" template parameter in serialization implementation.
The implementation of each class' serialization/deserialization is no longer
passed within a macro. The implementation now lies within a template of form:
template <typename T, typename Stream, typename Operation>
inline static size_t SerializationOp(T thisPtr, Stream& s, Operation ser_action, int nType, int nVersion) {
size_t nSerSize = 0;
/* CODE */
return nSerSize;
}
In cases when codepath should depend on whether or not we are just deserializing
(old fGetSize, fWrite, fRead flags) an additional clause can be used:
bool fRead = boost::is_same<Operation, CSerActionUnserialize>();
The IMPLEMENT_SERIALIZE macro will now be a freestanding clause added within
class' body (similiar to Qt's Q_OBJECT) to implement GetSerializeSize,
Serialize and Unserialize. These are now wrappers around
the "SerializationOp" template.
Thus the read(...) and write(...) methods of all stream classes now have identical parameter lists.
This will bring these classes one step closer to a common interface.