[Qt-interest] QString::toStdWString() link error

[Tim Dewhirst]

Hello,

John Michael Zorko wrote:
> I'm trying to use the Windows version of Qt, and when I try to use 
> QString::toStdWString(), I get an unresolved external:
> 
> error LNK2019: unresolved external symbol "public: int __thiscall 
> QString::toWCharArray(wchar_t *)const " 
> (?toWCharArray at QString@@QBEHPA_W at Z) referenced in function "public: 
> class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class 
> std::allocator<wchar_t> > __thiscall QString::toStdWString(void)const " 
> (?toStdWString at QString@@QBE?AV?$basic_string at _WU?$char_traits at _W@std@@V?$allocator at _W@2@@std@@XZ)
> C:\Users\Administrator\work\fw40\jmz_acl\build\bin\Debug\QtAdmin.exe : 
> fatal error LNK1120: 1 unresolved externals
> 
> ... do I need to build Qt with a special flag or some other way to 
> enable QString::toStdWString()?

Check the default flags in mkspec/win32-msvc*/qmake.conf; you're looking 
to see if wchar_t is enabled as a built in type or not. In my qmake.conf 
I currently have:

QMAKE_CFLAGS		= -nologo -Zm200 -Zc:wchar_t-

i.e. wchar_t is not a built in type and is probably defined as a ushort 
or similar.

I suspect the setting differs between the Qt DLL and your application.

Tim