Question

I really like using the _countof() macro in VS and I’m wondering if there is an OS-generic implementation of this in Qt.

For those unaware, _countof() gives you the number of elements in the array. so,

wchar_t buf[256];

_countof(buf) => 256 (characters)
sizeof(buf) => 512 (bytes)

It’s very nice for use with, say, unicode strings, where it gives you character count.

I’m hoping Qt has a generic version.

Answer 1

_countof is probably defined like this:

#define _countof(arr) (sizeof(arr) / sizeof((arr)[0]))

You can use a definition like this with any compiler and OS.

If there is no such macro provided by Qt you can simply define a custom one yourself in one of your header files.