Smart pointers are tricky, and automatic memory management is even
trickier, and I just created a template that does both. I swapped it in
for existing code in MySQL++ that used value semantics and it passes the
test suite, but I'd still appreciate someone else taking a look at it.
http://svn.gna.org/viewcvs/mysqlpp/trunk/lib/refcounted.h?view=markup
This is part of a general effort toward improving the way MySQL++
handles memory and object copies.
The particular need that sparked the creation of this template is that
in released MySQL++ versions, you cannot use a Row object after the
Result/ResUse object that created it is destroyed or reused itself.
This doesn't seem to catch too many newbies, but we do see it from time
to time.
I built a similar, but more primitive, mechanism last week for ColData,
which should improve performance of field access greatly: v2.3 copied
each field two or three times on every access, because it had to do
everything with value semantics to avoid similar problems to the one
described above. I hope to move ColData's buffer management to this new
template, but I'm not yet certain how it's going to work yet.
And yes, I am aware that this wheel has already been invented. It's in
Boost, for instance, but the last time I brought up the possibility of
making Boost a dependency of MySQL++, it was shot down so violently that
the detritus from the explosion settled in a thin even layer of powdery
ash over six counties.
