Including verify.h in C++ with C linkage

[Alex]

Hello, I'm trying to use C++ in a project that uses Gnulib, and I need
to use C linkage around a statement that eventually includes verify.h.
However, this leads to the following error message:

  ./lib/verify.h:178:1: error: template with C linkage
   template <int w>

Any way to successfully include this file in this context would be
appreciated.

Thanks for reading.