QHostAddress is one of the few classes in Qt which is pimpl'd but not implictly shared, making it suprisingly expensive to copy around, return by value and so on. Being pimpl'd it is also still lacking a move constructor, like most of such types in Qt. Remove a bit of the surprise factor and make it implictly shared. In practice this means making it eagerly parse host addresses from strings. Since it was entirely implemented out of line, replacing it with a implictly shared implementation is binary compatible. [ChangeLog][QtNetwork][QHostAddress] QHostAddress is now implicitly shared. Change-Id: Ia7ff94efcb74e7321b7607cd690c5c162f685605 Reviewed-by: Richard J. Moore <rich@kde.org>