View Compilation Error

0_0_38178951_20895.cpp: In member function 'std::tuple<int, C, L> C::inverse(const C&) const':
0_0_38178951_20895.cpp:465:60: error: too many arguments to function 'constexpr std::tuple<typename std::__decay_and_strip<_Elements>::__type ...> std::make_tuple(_Elements&& ...) [with _Elements = {}]'
         if (c == a.c) return mt(1, {c, r * r / a.r}, null_l);
                                                            ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/functional:55:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/x86_64-w64-mingw32/bits/stdc++.h:70,
                 from 0_0_38178951_20895.cpp:1:
GCC4.9.2/x86_64-w64-mingw32/include/c++/tuple:893:5: note: declared here
     make_tuple(_Elements&&... __args)
     ^
0_0_38178951_20895.cpp:465:60: error: could not convert 'std::make_tuple<{}>()' from 'std::tuple<>' to 'std::tuple<int, C, L>'
         if (c == a.c) return mt(1, {c, r * r / a.r}, null_l);
                                                            ^