bjam should honor include paths order

[pisymbol@…]

Currently bjam does not honor include paths and sorts things alphabetically as an speed optimization (I believe it has to do with comparing sets of paths for equivalence). In reality, bjam should honor include path order not only within a <include> attribute but also within a project hierarchy itself.

Here is a great thread with a lot of good discussion about the issue and what I have in mind for bjam:

​http://www.nabble.com/Sorting-include-headers-td19995752.html

[anonymous]

This is indeed a very good proposal. I am currently finding myself with the problem that a particular path NEEDS to be included before another one, and there is just no way that this works with bjam, is there?

[Vladimir Prus]

There is, just put:

<include>a&&b

in requirements for relevant metatarget or project.

[Steven Watanabe]

Unfortunately, this isn't completely foolproof. Given, <include>b&&a <include>a we'll end up with a b a.

It would work better if we used a topological sort. Isn't there already something like this for libraries?

[Vladimir Prus]

Hmm, I swear the plan was to put values with "&&" to the front of the list, before splitting, but I cannot see the evidence this is actually done in the current code.

topological sort would work. another alternative, of course, it just don't sort include properties, but the performance consequences of that are still uncearl.