The change in commit 1f19ac4d (Features: Adjust cxx_variadic_templates
unit test for GNU < 4.7., 2015-01-11) pacified GNU 4.6, but leaves
SolarisStudio 12.4 complaining:
"cxx_variadic_templates.cpp", line 5: Error: Partial specialization for Interface<Is...> has identical arguments.
1 Error(s) detected.
Implement a preprocessor test for using the partial specialization
workaround needed by GNU 4.6.
The unit test for this fails with GNU 4.6:
Building CXX object CMakeFiles/test_cxx_variadic_templates.dir/cxx_variadic_templates.cpp.o
CompileFeatures/cxx_variadic_templates.cpp: In static member function ‘static int Interface<I, Is>::accumulate()’:
CompileFeatures/cxx_variadic_templates.cpp:18:31: sorry, unimplemented: cannot expand ‘Is ...’ into a fixed-length argument list
CMakeFiles/test_cxx_variadic_templates.dir/build.make:54: recipe for target 'CMakeFiles/test_cxx_variadic_templates.dir/cxx_variadic_templates.cpp.o' failed
The workaround is to use a specialization:
http://stackoverflow.com/questions/1989552http://stackoverflow.com/questions/11297376
Expect cxx_variadic_templates to implement N2555.
N2555 is essentially a bugfix and predates most compiler releases which
aimed to experimentally support variadic templates.