Re: [boost] [modularization] Modularizing Boost (modularization)

Subject: Re: [boost] [modularization] Modularizing Boost (modularization)
From: Edward Diener (eldiener_at_[hidden])
Date: 2013-10-21 15:25:02

On 10/21/2013 2:49 PM, Jeremiah Willcock wrote:
> On Sat, 19 Oct 2013, Edward Diener wrote:
>
>> On 10/19/2013 4:39 PM, Jeremiah Willcock wrote:
>>> On Sat, 19 Oct 2013, Edward Diener wrote:
>>>
>>>>> I had thought going the other way would be better: the files in
>>>>> Boost.Graph that property map code depends on don't themselves use
>>>>> much
>>>>> other graph code.  Thus, they can be moved to Boost.PropertyMap
>>>>> without
>>>>> too much work, and that keeps all of the property map types that are
>>>>> there now in that library.  There are other property map types
>>>>> (sequential and parallel) in Boost.Graph that should likely also be
>>>>> moved even though they don't need to be for dependency reasons.
>>>>
>>>> If you do that it looks like you are then keeping a dependency for
>>>> property_map on multi_index, serialization, and optional. I am not
>>>> saying this is wrong if you feel that a distributed_property_map
>>>> really should be part of property_map, since those addititional
>>>> libraries are very useful for Boost libraries. I just wanted to point
>>>> that out. Whereas the more normal non-distributed property map does
>>>> not need to use those libraries AFAICS.
>>>>
>>>> Another option is to have distributed_property_map be a separate
>>>> libray of its own. More work, obviously, but this would create a more
>>>> minimal set of dependencies for property_map itself.
>>>
>>> A separate library might make more sense, actually.  Another option
>>> would be for property_map/parallel to be treated as a separate library
>>> without being moved in the Boost tree.
>>
>> I think that would be fine actaully.
>>
>> For that to work you will need to move the specializations of
>> distributed_property_map from their places in property_map.hpp and
>> vector_property_map.hpp to the property_map parallel directory as
>> separate files with theier own names, as well as remove the header
>> file inclusions for the parallel subdirectory in the otiginal files. I
>> think that would satisfy the end-user who wanted to use property_map
>> without having to drag in those dependencies for
>> distributed_property_map.
>>
>> Also the distributed_property_map should probably then be documented
>> as part of property_map rather than as part of graph, although graph
>> could have the appropriate link to that documentation.
>>
>> Similarly tests for distrubuted_property_map should be part of that
>> implementation rather than graph, and the correct header files
>> referenced.
>
> I have done the rearrangement of header files and namespaces, but not
> the tests, examples, or documentation yet.  There are still likely
> circular dependencies because of the compatibility #includes I left in
> (see my other email about that).

See my response to the other e-mail. If you agree with it the tests just 
need to have some of the #includes change and of course the ones in 
graph now for distributed property maps should be moved to property_map 
instead.

BTW thanks very much for working on all this. Your decision to keep 
distributed property maps in property_map is the right decision and the 
only reason I initially thought of moving the distributed property maps 
to graph was because I did not feel comfortable trying to figure out how 
to move the necessary graph support code into property_map.