CODEWITHSUNDEEP
c++typeswchar-t
Shadi
Shadi

Reputation: 1771

C++ wchart_t warning: character constant too long for its type

// update 1:

Code Blocks 16.01
GCC 4.9.2
Windows 10

I am trying to understand:

  1. What is the use of wchar_t?
  2. What is the difference between char16_t and wchar_t?
    I know char16_t is guaranteed to be 16-bit in size, but in this particular case both of them are the same size.
  3. What is The proper literals for each char type?

Program goal:

// end update 1

When I compile the following code:

#include <iostream>

int main(void)

{
    std::cout << sizeof(wchar_t) << "\n";
    for (wchar_t ch = u'\u0000'; ch <= u'\uffff'; ++ch)
        std::wcout << " " << ch;

    std::cout << "\n\n\n";
}

I got the following warning: "character constant too long for its type" on the line of the for statement.

I ran the program and I got this:output .

I searched the net and all what I could find is that wchar_t size is implementation defined, but even so, it is 2 bytes on my system. I think it is big enough.

Q1: Why I got the warning?
Q2: Why there was a few number of characters in the output? I expected thousands of them.

Upvotes: 0

Views: 1563

Answers (2)

Davislor
Davislor

Reputation: 15154

The following might work more as intended, displaying every printable codepoint from U+0000 to U+FFFF as Unicode. Be sure to set your console font to a Unicode font.

#include <cstdlib>
#include <cwctype>
#include <locale>
#include <iostream>

#if _WIN32 || _WIN64
// Windows needs a little non-standard magic for this to work.
#include <io.h>
#include <fcntl.h>
#include <locale.h>
#endif

using std::wint_t;
using std::iswprint;

void init_locale(void)
// Does magic so that wcout can work.
{
#if _WIN32 || _WIN64
  // Windows needs a little non-standard magic.
  constexpr char cp_utf16le[] = ".1200";
  setlocale( LC_ALL, cp_utf16le );
  _setmode( _fileno(stdout), _O_WTEXT );
#else
  // The correct locale name may vary by OS, e.g., "en_US.utf8".
  constexpr char locale_name[] = "";
  std::locale::global(std::locale(locale_name));
  std::wcout.imbue(std::locale());
#endif
}

int main(void)
{
    init_locale();

    for ( unsigned long i = 0; i < 0x10000UL; ++i )
      if (iswprint(static_cast<wint_t>(i)))
        std::wcout << static_cast<wchar_t>(i);

    std::wcout << std::endl;

    return EXIT_SUCCESS;
}

Upvotes: 2

Felipe Lopez
Felipe Lopez

Reputation: 416

When I run this code it runs fine:

int main(void)

{
    std::cout << sizeof(char16_t) << "\n";
    for (char16_t ch = u'\u0000'; ch <= u'\uffff'; ++ch)
        std::wcout << " " << static_cast<char>(ch);

    std::cout << "\n\n\n";
}

Upvotes: 0

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