Question: I'm compiling a trivial C++ file `Temp.cpp`:

```
#include <string>
int main() { std::wstring s; }

```

With the command line:

```
cl.exe /MD /Iinc\api\crt\stl60 /Iinc\crt /Iinc\api C:\Temp.cpp
       /LibPath:lib\wxp\i386 /LibPath:lib\crt\i386
       /link /LibPath:lib\wxp\i386 /LibPath:lib\crt\i386

```

in the WDK 7.1 Windows XP Free Build Environment.

I get link errors like (LNK2019):

```
unresolved external symbol "__declspec(dllimport) public: __thiscall
    std::basic_string<wchar_t,struct std::char_traits<wchar_t>,
    class std::allocator<wchar_t> >::~basic_string<wchar_t,
    struct std::char_traits<wchar_t>,class std::allocator<wchar_t> >(void)"
    (__imp_??1?$basic_string@_WU?$char_traits@_W@std@@V?$allocator
     @_W@2@@std@@QAE@XZ) referenced in function _main

```

If I use `string` instead of `wstring`, it works.

What's the cause of the problem? How can I use `wchar_t`-based types in my source file?

Answer: 
The likely fix would be to set /Zc:wchar\_t- to turn off wchar\_t as an intrinsic type. STL6 doesn't have great support for /Zc:wchar\_t which is the default since at least VC7.1, perhaps earlier.

Meta: Please don't use the STL60 version of STL. This version from 1998 lacks a large number of bug fixes, performance improvements and standards-conformance work that you can find in a modern STL. If you are using the VC compiler toolchain the free VC++ express includes STL.

Martyn
VC6 doesn't support the `wchar_t` *type* , it had a `typedef` for `unsigned short`. The linker would only be able to find `std::basic_string<unsigned short>` in the "stl60" lib.