Question

I have a code as following

ApplicationSetting.h

FOUNDATION_EXPORT BOOL *const TEST_MODE;

ApplicationSetting.m

#ifdef DEBUG
BOOL *const TEST_MODE = YES;
#else
BOOL *const TEST_MODE = NO;
#endif

The above .m file’s code gives me this warning

Incompatible integer to pointer conversion initializing 'BOOL *const' 
(aka 'signed char *const') with an expression of type 'signed char'; 

But, if I change it to be come like this

#ifdef DEBUG
BOOL *const TEST_MODE = NO;
#else
BOOL *const TEST_MODE = YES;
#endif

It works just fine without any warning.

Do you have any idea how could this happens?

Answer 1

You really meant to write a value:

FOUNDATION_EXPORT const BOOL TEST_MODE;

…BOOL is not an objc object, it is a signed char.

as far as the error, the compiler complains because you are assigning numeric values to the pointer value — where only 0 (aka NULL) is acceptable to the compiler, and any other number (YES is 1) will produce the error/warning.

P.S. Just use bool.