View Compilation Error

0_0_35777856_32038.cpp: In function 'int main()':
0_0_35777856_32038.cpp:20:41: error: wrong number of template arguments (0, should be 1)
         sort(vt.begin(), vt.end(), less<>());
                                         ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/string:48:0,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/locale_classes.h:40,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/ios_base.h:41,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/ios:42,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/ostream:38,
                 from GCC4.9.2/x86_64-w64-mingw32/include/c++/iostream:39,
                 from 0_0_35777856_32038.cpp:5:
GCC4.9.2/x86_64-w64-mingw32/include/c++/bits/stl_function.h:367:12: error: provided for 'template<class _Tp> struct std::less'
     struct less : public binary_function<_Tp, _Tp, bool>
            ^