define: DUK_OPT_FUNCPTR16
introduced: 1.1.0
related:
  - DUK_OPT_FUNCPTR_ENC16
  - DUK_OPT_FUNCPTR_DEC16
tags:
  - lowmemory
  - experimental
description: >
  Enable "compression" of arbitrary C function pointers into an unsigned 16-bit
  value.  Use together with DUK_OPT_FUNCPTR_ENC16 and DUK_OPT_FUNCPTR_DEC16.

  Pointers compressed are any C function pointers.  Also NULL pointer must
  encode and decode correctly.

  Currently it is required that NULL encodes to integer 0, and integer
  0 decodes to NULL.  No other pointer can be encoded to 0.

  NOTE: This feature option is currently unimplemented, i.e. Duktape won't
  compress any function pointers at the moment.  It might not be necessary
  to support a NULL function pointer (uncertain until taken into use).