c++ - How to initialize char array using hex numbers?

Question

I use utf8 and have to save a constant in a char array:

const char s[] = {0xE2,0x82,0xAC, 0}; //the euro sign

However it gives me error:

test.cpp:15:40: error: narrowing conversion of ‘226’ from ‘int’ to ‘const char’ inside { } [-fpermissive]

I have to cast all the hex numbers to char, which I feel tedious and don't smell good. Is there any other proper way of doing this?

Answer 1

char may be signed or unsigned (and the default is implementation specific). You probably want

  const unsigned char s[] = {0xE2,0x82,0xAC, 0}; 

or

  const char s[] = "xe2x82xac";

or with many recent compilers (including GCC)

  const char s[] = "€";

(a string literal is an array of char unless you give it some prefix)

See -funsigned-char (or -fsigned-char) option of GCC.

On some implementations a char is unsigned and CHAR_MAX is 255 (and CHAR_MIN is 0). On others char-s are signed so CHAR_MIN is -128 and CHAR_MAX is 127 (and e.g. things are different on Linux/PowerPC/32 bits and Linux/x86/32 bits). AFAIK nothing in the standard prohibits 19 bits signed chars.