Resizing

Julia does not currently have a well developed interface for changing the size of collections. Resizing provides common methods for growing and shrinking collections. Although the relative position where a resizing method is executed may vary by method and collection type, a common pattern makes them straightforward to use and overload for new collections. For example, the following methods are responsible for growing a collection from the last index:

• Resizing.unsafe_grow_end!(collection, n): assumes that all necessary conditions for growing collection by n elements from the last index are met without checking.
• Resizing.grow_end!(collection, n): Calls Resizing.unsafe_grow_end!(collection, n) if it can determine that collection can safely grow by n elements from the last index, returning true if successful.
• Resizing.assert_grow_end!(collection, n): Calls Resizing.grow_end!(collection, n). If false is returned it throws an error, otherwise returns nothing.

Note that grow_end! and unsafe_grow_end! must be defined for each new collection type, but assert_grow_end! can rely completely on the former two methods.

This same pattern exists for shrinking or growing at the beginning, end, or a specified index.