View Compilation Error

0_0_14765489_8676.cpp: In function 'int main(int, const char**)':
0_0_14765489_8676.cpp:86:20: error: reference to 'tm' is ambiguous
     sn[mem].mask = tm(m);
                    ^
0_0_14765489_8676.cpp:53:14: note: candidates are: unsigned int tm(int)
 unsigned int tm(int m) {
              ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/cwchar:44:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/postypes.h:40,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/char_traits.h:40,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/string:40,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/stdexcept:39,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/array:38,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/tuple:39,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_map.h:63,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/map:61,
                 from 0_0_14765489_8676.cpp:10:
GCC4.9.2/x86_64-w64-mingw32/include/wchar.h:895:10: note:                 struct tm
   struct tm {
          ^