Intel compiler error with tuple_storage

[brandonneth]

When compiling RAJA with Intel+OpenMPI (19 or 21), I get the following error:

In file included from /g/g15/neth3/RAJA/include/RAJA/util/camp_aliases.hpp(31),
                 from /g/g15/neth3/RAJA/include/RAJA/policy/PolicyBase.hpp(21),
                 from /g/g15/neth3/RAJA/include/RAJA/index/IndexSet.hpp(29),
                 from /g/g15/neth3/RAJA/include/RAJA/index/IndexSetBuilders.hpp(23),
                 from /g/g15/neth3/RAJA/src/AlignedRangeIndexSetBuilders.cpp(24):
/g/g15/neth3/libs/include/camp/tuple.hpp(110): error: cannot overload functions distinguished by return type alone
      CAMP_HOST_DEVICE CAMP_CONSTEXPR14 Type& get_inner() noexcept { return val; }
                                              ^

In file included from /g/g15/neth3/RAJA/include/RAJA/util/camp_aliases.hpp(31),
                 from /g/g15/neth3/RAJA/include/RAJA/policy/PolicyBase.hpp(21),
                 from /g/g15/neth3/RAJA/include/RAJA/index/IndexSet.hpp(29),
                 from /g/g15/neth3/RAJA/include/RAJA/index/IndexSetBuilders.hpp(23),
                 from /g/g15/neth3/RAJA/src/AlignedRangeIndexSetBuilders.cpp(24):
/g/g15/neth3/libs/include/camp/tuple.hpp(134): error: cannot overload functions distinguished by return type alone
      CAMP_HOST_DEVICE CAMP_CONSTEXPR14 Type& get_inner() noexcept
                                              ^

make[2]: *** [CMakeFiles/RAJA.dir/src/AlignedRangeIndexSetBuilders.cpp.o] Error 2