error C2678 binary '<' : no operator found for map>

How can I resolve the following compiler error:

xstddef(180): error C2678: binary '<' : no operator found which takes a left-hand operand of type 'const std::string' (or there is no acceptable conversion)
          tuple(572): could be 'bool std::operator <(const std::tuple<> &,const std::tuple<> &)'
          while trying to match the argument list '(const std::string, const std::string)'
          xstddef(179) : while compiling class template member function 'bool std::less<_Ty>::operator ()(const _Ty &,const _Ty &) const'
          with
          [

显式include string，在map前面

#include <string> // <== IN PARTICULAR THIS ONE
#include <map>