tree df5dae5b1ade224658a29dd954101cb119dd7b89
parent 203e078fdf31b147312da667cb6a4674e60ffbca
author Kalev Lember <klember@redhat.com> 1612798573 +0100
committer Kalev Lember <klember@redhat.com> 1612802511 +0100

gmacros: Guard C++ code with extern "C++"

A number of C++ consumers are (incorrectly) including glib headers in an
extern "C" block, which leads to build failures such as:

/usr/include/c++/11/type_traits:56:3: error: template with C linkage
   56 |   template<typename _Tp, _Tp __v>
      |   ^~~~~~~~

We can easily escape that on the glib side by putting the C++ code in an
extern "C++" block. Which technically it's a bug on the consuming
program's side, I think it's pragmatic here to work this around on the
glib side.