On Nov 24, 2008, at 8:24 AM, Rick Gutleber wrote:
> Just out of curiosity, since mysqlpp::String is _not_ derived from
> std::string, I was wondering about the decision process behind this,
> since it seems to be a natural thing to do.
mysqlpp::String is designed to be invisible to MySQL++ users, for the
most part. It is simply what MySQL++ uses when it needs to return SQL
field data to a caller. Most of the time, it converts instantly to
int foo = row;
There's a String in there, you just don't see it.
We parallel the std::string interface is only because, well, why not?
It's a perfectly reasonable model to follow, and familiar to any C++
That said, it's intentionally not a complete clone of std::string. We
don't copy anything over that can be used to modify the string. This
is, again, because it's only an output container. We have a
legitimate need for a different kind of wheel, so while we keep the
pointless differences down as much as we reasonably can, the goal is
not to reinvent std::string.
Besides which, it lets us do reference counted buffer management among
MySQL++ classes, rather than rely on std::strings everywhere to get
CoW behavior. Look at SQLBuffer.