Hi, 
I made a string class for wide characters. 
this is the code - 

using namespace std; 
class MyString 
{ 
public: 
wstring wStr; 
MyString () {wStr = L"";} 
MyString (wstring str) {wStr = str;} 
}; 

int main() 
{ 
wstring firstName = L"Vipul"; 
MyString myStr (firstName); 
wprintf(L"%s", myStr.wStr); 
return 0; 
} 

But it gives error - cannot pass objects of non-POD type class std::wstring through '...'; call will abort at runtime. 

What are POD type classes and non-POD type classes? 
And how to solve this? I want to make my string class platform independent. 

Thanks,