Wrappers exist for simple objects such as math classes (like vectors or matrices). They are generally fully implemented C++ classes with public constructors and destructors. API methods may return a wrapper, which you are then responsible for—leaving scope will usually be adequate for deleting the wrapper. You are also free to allocate and deallocate them as necessary. In the previous example ( Building a curve using a plug-in), MPointArray and MDoubleArray are wrappers. You always own the wrapper that you reference.
The constructor of a wrapper will in most cases call new to allocate the internal Maya object. As a result, if a wrapper is declared in a heavy loop memory will be allocated and de-allocated repeatedly.
This tip does not apply to static wrapper classes such as MGlobal.
