Resize

If you look at the Str code closely, you might notice that all allocation of Str::data is done by calling resize(). This is done for the following reasons:

• The resize() function correctly handles the STR_ALLOCATED, STR_TIME_EFFICIENT and STR_EXTRA_BUFFER bits in the data structure.
• resize() also correctly handles the case where Str::data == 0
• Calling resize() puts the logic of when to resize the buffer in one place, making it easy to change.
• Calling resize() puts the malloc() call in one place. This makes it easier to change to a different allocation method.