Re: [boost] [multi_index] use cases for iterator_to()

From: Paul Rose (prose_at_[hidden])
Date: 2007-06-11 13:09:06

>> I guess I'l finally include it, but it'd be so much nicer if we could

>> find a conclusive use case. I've also thought about legacy interfaces

>> requiring raw pointers, if only we could come up with a simple 
>> specific scenario on that line. 

Here's a case that is kind of an inverse of the legacy case:

I sometimes develop DLL's in windows that are used by a team of C
delveopers.  I feel free to use C++ (including boost.multindex) in the
implementation of the DLL, but the interface is straight C.  Part of
that interface may give out an opaque pointer to an object owned by a
boost.multiindex.   

  /* C interface */
  typedef struct FooTag Foo;
  Foo *makeFoo(int x, int y, int z);
  void killFoo(Foo *);

  void flushFoo(Foo *);
  void flushAllFoos();

Latter they call in with that opaque poitner as a parameter.  I could
look up the node in the container, but iterator_to would be better.

I don't consider this "legacy" because I'm writing a new library to
support new development, but I am contrained by the interface language
("C" vs "C++").

Paul