[opam-devel] [Caml-list] [ANN] IOCaml v0.3

Hezekiah M. Carty hez at 0ok.org
Tue Feb 18 12:18:27 GMT 2014

On Fri, Feb 14, 2014 at 6:12 AM, Anders Fugmann <anders at fugmann.net> wrote:
> On 02/14/2014 11:49 AM, Anil Madhavapeddy wrote:
>> The too-new library is almost certainly the case -- although unfortunately
>> I don't have the 3.2.4 version in my Homebrew anymore and so the switch
>> doesn't work (they don't keep older versions around like OPAM does, I
>> believe).
>> $ brew switch zmq 3.2.4
>> Error: zmq does not have a version "3.2.4" in the Cellar.
>> Versions available: 4.0.3
>> Are the interfaces very different between the versions to support both, or
>> does this require a big rev to your bindings?
> I do not think that is feasible.
> ZMQ 3.x.x and ZMQ 4.x.x has different wire formats, so they are not
> interchangeable. Also the header files have changed, so I assume that would
> not be possible to have a version that supports both (i.e. based on the C
> library installed).

A slightly off-topic clarification - A program using ZMQ 4.x.x can
speak to one using ZMQ 3.x.x or ZMQ 2.x.x (and 3.x.x can speak to
2.x.x) as long as the newer program only uses socket types supported
by the older library.  I don't think that there is C ABI or API
compatibility across major ZMQ releases.


More information about the opam-devel mailing list