Subject: Re: [boost] [chrono] Dependency on math?
From: alex (alexhighviz_at_[hidden])
Date: 2015-01-09 17:43:07
Peter Dimov wrote
> Sent: 09 January 2015 16:42
> To: boost_at_[hidden]
> Subject: Re: [boost] [chrono] Dependency on math?
>
> alex wrote:
> > As I understand it, if library X depends on library Y and Y depends on
> > Z, then X is said to depend on Z. I can understand as packages are
> > created based on the library dependency graph:
> >
> > [ To package X we must package all libraries on which X depends.]
> >
> > However, the reality is that the file-dependencies of X do not
> > necessarily include Z. Why would you not package only the files upon
> > which the desired library depends?
>
> Because the package for X only contains X's files, not its dependencies.
If X
> depends on a file from Y, then Y's package must be installed to get Y's
file.
> And since Y is now installed, if it requires building, Z needs to be
installed as
> well; but even if it doesn't require building, having Y installed but
unusable
> is not good from usability point of view.
>
Thanks for clarifying. I must say I am not convinced by the usability
argument. Having just the files of Y and not the build makes library X
usable. And X is what the user asked for. So, from a usability point of view
it is perfect.
Y must not be build, but there are good arguments for Y to be build. However
there are also counter arguments as there clearly is an unhealthy incentive
now to fragment libraries, to duplicate code and to fix things that are not
broken.