Re: [PATCH] Avoid having GNULIB_NAMESPACE::func always inject references to rpl_func

[Paul Eggert]

Thanks, I installed your two recent patches. I don't know C++ well; perhaps 
Bruno or another reviewer can double-check if they have the time.

I noticed that with the patches installed, the command './gnulib-tool --test 
--with-c++-tests frexp frexpl frexpf frexp-nolibm' fails with diagnostics like 
the following (Fedora 24, GCC 6.2.1 20160916)

make[3]: Entering directory 
'/home/eggert/src/gnu/gnulib/testdir4584/build/gltests'
g++ -DHAVE_CONFIG_H -I. -I../../gltests  -DGNULIB_STRICT_CHECKING=1 -I. 
-I../../gltests -I.. -I../../gltests/.. -I../gllib -I../../gltests/../gllib 
-MT test-math-c++.o -MD -MP -MF .deps/test-math-c++.Tpo -c -o test-math-c++.o 
../../gltests/test-math-c++.cc
../../gltests/test-math-c++.cc:37:45: error: invalid static_cast from type 
‘<unresolved overloaded function type>’ to type ‘int (*)(float)’
     = static_cast<rettype(*)parameters>(func)
                                             ^
../../gltests/test-math-c++.cc:32:3: note: in expansion of macro 
‘OVERLOADED_CHECK’
   OVERLOADED_CHECK (func, rettype1, parameters1, _1); \
   ^~~~~~~~~~~~~~~~


However, similar failures occur even without the patches (the patches fix one of 
the failures, actually) so this is not a regression.