Boost header files are in
When you install libboost-all-dev, a number of other specific packages are installed as dependencies.
These packages' also provide libraries and headers through an indirect mechanism. They declare packages with version numbers in their names as dependencies, and those packages are the ones that actually contain the library binaries and header files.
For example, libboost-dev is one of the packages installed as a dependency of
libboost-dev declares just one package as a dependency. In 12.04, this package is libboost1.46-dev
libboost1.46-dev has dependencies too but its main purpose is to provide files directly. You can see these in its file list.
Boost header files have a
.hpp extension. (Note that just
.h is common for most other C++ libraries.) Many
.hpp files are listed in
libboost1.46 -dev's file list:
...and so forth.
You'll notice all those files are inside
To find this information, I used packages.ubuntu.com, the online Ubuntu packages database.
People interested in finding specific information about what files are provided by Boost packages in their Ubuntu release, what packages provide them, and where they will be located on disk once installed can find that there.
Or, to get you started, here's a query that shows the
libboost-all-dev package entries for all currently supported Ubuntu releases (and several others).
I got that by searching under Search package directories, changing Distribution to "any," and using
libboost-all-dev as the search keyword.