LINK ERROR in VC++

I needed help making sense out of the following LNK error which i am getting.

SwitchFunctions error LNK2019: unresolved external symbol "__declspec(dllimport) ??$?8DU?$char_traits@D@std@@V?$allocator@D@1@@std@@YA_NABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@0@PBD@Z" (__imp_??$?8DU?$char_traits@D@std@@V?$allocator@D@1@@开发者_如何学Gostd@@YA_NABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@0@PBD@Z) referenced in function "??$find@Viterator@?$vector@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$allocator@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@@std@@PBD@std@@YA?AViterator@?$vector@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$allocator@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@@0@V120@0ABQBD@Z" (??$find@Viterator@?$vector@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$allocator@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@@std@@PBD@std@@YA?AViterator@?$vector@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@V?$allocator@V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@2@@0@V120@0ABQBD@Z)

Have you checked whether you have included all necessary dlls or lib files in your project settings?

Such an error usually indicate that you have used a function which definition is found, but implementation is not. Usually in the case of external libraries, the implementation is inside a dll or a static lib. Failure to provide the dll or the static lib will cause the linking to fail.

Which version of Visual Studio are you using? This might be relevant for VS2005: Link error using a CString derived class from a DLL