[SOLVED] C char constant

Issue

I have code:

static uint64_t password = 'password';

GCC say:

warning: character constant too long for its type static uint64_t password = 'password';

If I do so:

static uint64_t password = 'pass';

GCC say:

warning: multi-character character constant [-Wmultichar] static uint64_t password = 'pass';

That is, it turns out that sizeof(char) = 2, but is it not so, or is it not?

Solution

sizeof( char ) is guaranteed to be 1, by definition.

C17§6.5.3.4¶4 When sizeof is applied to an operand that has type char, unsigned char, or signed char, (or a qualified version thereof) the result is 1. [...]

---

'...' is an int.

C17§6.4.4.4¶10 An integer character constant has type int. [...]

You apparently have a system where sizeof( int ) == 4, which is why you could specify 4, but not 8 characters.

---

Note that it's really weird to use a multi-character constant.

And it's not portable.

C17§6.4.4.4¶10 [...] The value of an integer character constant containing more than one character (e.g., 'ab' ), or containing a character or escape sequence that does not map to a single-byte execution character, is implementation-defined. [...]

Answered By - ikegami

Answer Checked By - Gilberto Lyons (WPSolving Admin)