2009/9/16 Brett Blackham <brett.blackham@gmail.com>:

>
>
> So MemoryPointer is like calling malloc and returning a pointer to
> it.

Correct.  The native memory gets garbage collected for you when the
MemoryPointer instance no longer has any hard references to it.

> I had tried just sending address to Pointer.new in hopes that it could
> handle an Int as well as an existing pointer. But it doesn't appear to
> work.

It works in master, so it must have been added after the 0.4.0 release.

Just do the test in ruby land then, and only wrap the address if not
already a pointer.

>

>>> require 'ffi'

> => true

>>> address = FFI::Pointer.new(5)

> => #<Native Pointer address=0x5>

>>> p = FFI::Pointer.new(address)

> TypeError: can't convert FFI::Pointer into Integer
>        from (irb):4:in `initialize'
>        from (irb):4:in `new'
>        from (irb):4
>

>>> address = FFI::MemoryPointer :pointer

> NoMethodError: undefined method `MemoryPointer' for FFI:Module
>        from (irb):5

>>> address = FFI::MemoryPointer.new :pointer

> => #<MemoryPointer address=0x155f140 size=8>

>>> p = FFI::Pointer.new(address)

> TypeError: can't convert FFI::MemoryPointer into Integer
>        from (irb):7:in `initialize'
>        from (irb):7:in `new'
>        from (irb):7
>