(arg) < (char *)4096 ? 0 : strlen( arg )

[deller]

can any tell me what the following statement means, here arg is a string, say: "foo".

(arg) < (char *)4096 ? 0 : strlen( arg )

thanks

especially this part: (arg) < (char *)4096

[MrViggy]

Well, technically, it's comparing (arg) to the value 4096 (casted to a char pointer). If arg is less then 4096, the whole expression will resolve to '0'; otherwise it will resolve to the length of arg (if arg is indeed a pointer to a character array).

Viggy

[SuperKoko]

Behavior is implementation-dependent, since mapping between integers and pointers, via reinterpret_cast, is implementation-defined.
Anyway, if it is under a Windows platform, and knowing that pointers under 0x400000 are not mapped to physical memory (thus accessing them do a segmentation fault), this strange code is perhaps due to someone which try to store different things in a pointer.
This arg pointer seems to be : Either a number/identifier in range [0,4096) or a character string.
This type of weird non-portable way to store either an identifier or a pointer is even used by the Win32 API with resource identifiers... With integers in range [0,65536)