On Sun, Sep 7, 2008 at 6:55 PM, Michael Fawcett <michael.fawcett@gmail.com>wrote:
On Sun, Sep 7, 2008 at 2:21 PM, Rene Rivera <grafikrobot@gmail.com> wrote:
That would be because AFAIK all Boost headers start with "boost/..." and don't reference local includes. But moving to preferring ("") will likely encourage library authors to rely on what is essentially non-portable compiler behavior. The use of (<>) includes is technically also non-portable but is currently universally portable or can be made that way.
So it sounds like libraries should prefer <>, and the only time "" should be used is in project specific headers (i.e. won't be reused). But then often times project specific code ends up being generalized into a library at a later date, at which point it should be <>, so shouldn't you just always use <> then?
I only use "" in source (.cpp) files for including headers that live in the same directory, in which case I don't qualify the filename w/ a directory prefix. I basically use <> for everything else, qualified w/ the top-most directory prefix (e.g. #include <boost/.../foo.hpp>). Using the directory-qualified includes is especially important in library headers so that the compiler is happy when building the library itself, as well as when building against the library. However, I find that always including in this fashion, even in stand-alone executables, makes it easier to move code into a library later. Using <> by default works well for me because I like to use -I to control include order. I like to specify a single -I for the library, and dont want the CPP to search the current directory first, which is what one of the compilers that I use will do if I use "". And perhaps I'm also a bit superstitious. ;-) Jon