I can't get the infinity symbol to print in Visual Studio 2019 using C-CodePudding

I'm trying to get the infinity symbol (∞) to print but I keeping getting garbage. I've tried everything mentioned here but nothing is working.

What I'm trying to accomplish is this

modifies strength by 9 ∞

I've tried

printf ("%c", 236);
printf ("%c", 236u);

and I get

modifies strength by 9 ì

I've tried

printf("∞");

and I get

modifies strength by 9 ?

I tried this

if ( paf->duration == -1 ){
    setlocale(LC_ALL, "en_US.UTF-8");
    wprintf(L"%lc\n", 8734);
    ch->printf("∞");

Just to see if I could get wprintf to print it but it completely ignores setlocale and wprintf and still gives me

modifies strength by 9 ?

I tried

if ( paf->duration == -1 ){
    std::cout << "\u221E";
    ch->printf("∞");

But got the this warning and error

Error   C2664   'int _CrtDbgReportW(int,const wchar_t *,int,const wchar_t *,const wchar_t *,...)': cannot convert argument 5 from 'int' to 'const wchar_t *'    testROS1a   C:\Program Files (x86)\Windows Kits\10\Include\10.0.19041.0\ucrt\malloc.h   164 
Warning C4566   character represented by universal-character-name '\u221E' cannot be represented in the current code page (1252)    testROS1a   C:\_Reign of Shadow\TEST\src\CPP\act_info.cpp   3724

which I can't make heads or tails of. I've exhausted the scope of my knowledge so does anyone know how to make this happen?

CodePudding user response：

This does the trick on my machine, windows code page (1252), not sure how universal this is though. I never really got to work a lot with unicode/localization stuff. And there always seems to be one more gotcha.

#include <iostream>
#include <io.h>
#include <fcntl.h>

const wchar_t infinity_symbol = 0x221E;

int main()
{
    // enable windows console to unicode
    _setmode(_fileno(stdout), _O_U16TEXT);
    std::wcout << infinity_symbol;
}

CodePudding user response：

To use the Windows command prompt with wide strings, change the mode as follows, printf/cout won't work until the mode is switched back. Make sure to flush between mode changes:

#include <iostream>
#include <io.h>
#include <fcntl.h>

using namespace std;

int main()
{
    // To use wprintf/wcout and output any BMP (<= U FFFF) code point
    int org = _setmode(_fileno(stdout), _O_U16TEXT);
    wcout << L'\u221e' << endl;
    wprintf(L"\u221e\n");

    fflush(stdout);
    _setmode(_fileno(stdout), org); // to switch back to cout/printf and default code page
    cout << "hello, world!" << endl;
    printf("hello, world!\n");
}

Output:

∞
∞
hello, world!
hello, world!

If you use UTF-8 source and your compiler accepts it, you can also change the code page of the terminal to 65001 (UTF-8) and it could work with printf as is:

test.c

#include <stdio.h>

int main() {
    printf("∞\n");
}

Console output:

C:\demo>cl /W4 /utf-8 /nologo test.c
test.c

C:\demo>chcp
Active code page: 437

C:\demo>test          ## NOTE: Wrong code page prints mojibake.
Γê₧                   ##       These are UTF-8 bytes interpreted incorrectly.

C:\demo>chcp 65001
Active code page: 65001

C:\demo>test
∞