Type Conversion Error

[rtr_18]

Hi!
I got the following error while adding an item to a Combobox.

error C2664: 'irr::gui::IGUIComboBox::addItem' : cannot convert parameter 1 from 'irr::core::stringc' to 'const wchar_t *'

Code: Select all

 irr::core::array<irr::core::stringc> ctyLst = SQLdb.Query("Select DISTINCT Team from Test");
 for(int i =0; i < ctyLst.size(); i++ )
 {
    m_pCountryCbo->addItem(ctyLst[i]);
 }

How to convert 'irr::core::stringc' to 'const wchar_t *'?

[bart]

Hi

I am not sure this is the fastest method but it works. First convert it to stringw and then use c_str()

Code: Select all

m_pCountryCbo->addItem(stringw(ctyLst[i]).c_str()); 

[slavik262]

Basically there's two types of strings - standard and wide. Normal strings are the ones you are probably used to working with (i.e. "Hello World!"). Wide strings use two bytes per character instead of just one and use the type wchar_t instead of char. They can support many other characters, such as unicode characters, etc. You can create a wide string by simply putting an L in front of the string (i.e. L"Hello World!"). Like bart suggested, Irrlicht has a string class for each (stringc for standard strings and stringw for wide ones) and can use them to convert between the two.

[vitek]

Wide strings use two bytes per character instead of just one and use the type wchar_t instead of char.

Not necessarily. The size of a wchar_t is platform dependent. For example, it is 4 bytes on recent versions of g++ on linux.

Code: Select all

[vitek@junta pointer]$ cat t.cpp
#include <stdio.h>

int main ()
{
  printf ("sizeof(wchar_t) = %u\n", sizeof(wchar_t));
  return 0;
}
[vitek@junta pointer]$ g++ t.cpp && ./a.out
sizeof(wchar_t) = 4

Like bart suggested, Irrlicht has a string class for each (stringc for standard strings and stringw for wide ones) and can use them to convert between the two.

I'm fairly certain that the Irrlicht string template is only good for translating strings that are representable in ASCII (i.e., the char value has to be between CHAR_MIN and CHAR_MAX).

Travis