[C++] Convert char* to wchar_t

[dodle]

I am trying to convert a char string to a wide char string.


#include <iostream>
using namespace std;

int main(int argc, char* argv[])
{
if (argc > 1)
{
wchar_t* arg1 = (wchar_t*) argv[1];
cout << arg1 << endl;
return 0;
}
else return 1;
}

Apart from the above, I have also tried these:

wchar_t* arg1 = argv[1];
http://www.cplusplus.com/reference/clibrary/cstdlib/mbstowcs/

wchar arg1[512];
mbtowcs(arg1, argv[1], 512);

I have also seen some suggest using "wcout" instead of cout:

wcout << arg1 << endl;
but "wcout" isn't found:

: error: `wcout' was not declared in this scope

[dwhitney67]

After a few moments of Googling, I found this (partial) solution:


#include <locale>
#include <iostream>
#include <string>
#include <sstream>
using namespace std ;

wstring widen( const string& str )
{
wostringstream wstm ;
const ctype<wchar_t>& ctfacet =
use_facet< ctype<wchar_t> >( wstm.getloc() ) ;
for( size_t i=0 ; i<str.size() ; ++i )
wstm << ctfacet.widen( str[i] ) ;
return wstm.str() ;
}

string narrow( const wstring& str )
{
ostringstream stm ;
const ctype<char>& ctfacet =
use_facet< ctype<char> >( stm.getloc() ) ;
for( size_t i=0 ; i<str.size() ; ++i )
stm << ctfacet.narrow( str[i], 0 ) ;
return stm.str() ;
}

int main()
{
{
const char* cstr = "abcdefghijkl" ;
const wchar_t* wcstr = widen(cstr).c_str() ;
wcout << wcstr << L'\n' ;
}
{
const wchar_t* wcstr = L"mnopqrstuvwx" ;
const char* cstr = narrow(wcstr).c_str() ;
cout << cstr << '\n' ;
}
}

The only caveat I have found with the code above is that second code-block in the main() function fails to perform its job. I think it has something to do with the locale used by the ostringstream.

But if all you want is to go from char* to wchar_t*, then just utilize the widen() function, as shown above.

[worksofcraft]

I presume the reason you want to go to wide chars is that you want to use non ascii. For this it is is handy to have a function that can read utf-8 sequences to make a wide char. Do beware though some wide char implementations are apparently not wide enough for unicode so I ended up making my own unicode type.

Someone told me there are standard library routines for converting to and from utf-8 but I had already written my own by then, but just in case you want to have a look anyway I'll attach my source code.

[dodle]

Sorry, I forgot to post that I had found a solution. I used the C++ function mbstowcs:


#include <iostream>
#include <stdlib.h>
using namespace std;

int main(int argc, char* argv[])
{
if (argc > 1)
{
wchar_t arg1[512];
mbstowcs(arg1, argv[1], 512);
wcout << arg1 << endl;
return 0;
}
else return 1;
}

The reason why I needed to convert to wide char was because I was doing some coding with WINAPI fuctions that required unicode strings.