Search content (.h files) of all (-dev) packages?

[Alexander Traud <pabstraud@compuserve.com>]

Recently, I stumbled over a change in Doxygen [1][2][3] which broke the online documentation of a project, I had to use. The fix is easy. However, realizing the issue is not easy (no error, warning, just subtle glitches in the docs). Long story short, I grepped all -dev packages and their header files installed on my machine. That way, I found projects affected and reported/fixed it upstream.

Question: Exists an (easy) way to 'grep' all headers files of all packages in Debian?

[1] <https://gcc.gnu.org/git/?p=gcc.git;h=f0b8834>
[2] <https://gcc.gnu.org/git/?p=gcc.git;h=014b6db>
[3] <https://gcc.gnu.org/git/?p=gcc.git;h=72ddd86>