error LNK2019

IQlog.obj : error LNK2019: unresolved external symbol "class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >
__cdecl Trim(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,bool,bool)" (?Trim@@YA?AV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@AAV12@ABV12@_N2@Z)
referenced in function "enum LOGGER_EC __cdecl LOGGER_Initialization(void)" (?LOGGER_Initialization@@YA?AW4LOGGER_EC@@XZ)

编译程序时出现以上错误，关键字已用红色标记。

其实就是没有找到Trim的实现。