Re: [boost] boost library interdepence

From: Kevlin Henney (kevlin_at_[hidden])
Date: 2000-05-03 15:04:15

In message <8epko4+im7r_at_[hidden]>, Gary Powell
<Gary.Powell_at_[hidden]> writes
>Question: Should a library in the vault or on the boost web page in 
>general require other boost libraries?
>
>Other than reusing boost/config.hpp, as a library writer, should I 
>make every effort to use all of the other boost libraries? Or should 
>every library be stand-a-lone, with no other boost files being 
>necessary.

I'm not sure that this is such a useful way of thinking about it. High
cohesion and low coupling imply that a library should depend on no more
or no less than it requires. Making an effort to reuse stuff for its own
sake doesn't seem (re)useful, and neither does intentionally avoiding
reuse -- and therefore duplicating functionality.

>On one hand, reuse is good. On the other hand tight linking is bad. A 
>I hate it when I download one library only to find I need eight more. 
>So if we do interlink libraries, it should be obvious to a user 
>downloading which other libraries we are dependent on.

It seems reasonable that a boost library can be standalone, or dependent
on the standard library and/or on another boost library. As a
recommendation, cycles between boost libraries should be avoided as
should dependencies on non-boost or non-std libs. As for the vaults,
dependencies on other vault submissions and accepted boost libs seems
fine, but not vice-versa.

Thoughts?
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  Kevlin Henney                   phone:  [phone]
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