2019年7月10日 · The so-called safe bool idiom is a misnomer, though -- dirty hack would be better suited. It is by no means safe, or expresses intent well. A bool communicates: "this is a …

2016年7月24日 · On error, (void *) -1 is returned, and errno is set to ENOMEM. Now, What's the significance of (void *) -1? What is the exact memory address it points to? (if it does at all) …

2012年7月24日 · A void * can be converted to any other pointer type without an explicit cast. You cannot dereference a void * or do pointer arithmetic with it; you must convert it to a pointer to a …

2012年11月9日 · However, it is not necessary for (void *) -1 not to be a valid address in order for shmat to work. It is merely necessary that a successful call to shmat never returns (void *) -1 …

The Linux Man Page for sbrk() states that upon failure, it returns (void*) -1. What is (void*) -1 and does it have any significance or is it simply a number that could never actually be a void* …

2009年8月18日 · On top of that, Douglas Crockford doesn't like void, so jslint will complain about it. Basically, since void is an operator, and not a value, it's confusing as hell, and spawns …

2010年7月28日 · Otherwise you would have surprising behaviors using pointer arithmetic like p+1 == p when p is void*. The standard way would be to use `char* for that kind of purpose …

gcc has an extension that treats sizeof (void) as 1. gcc is not a conforming C compiler by default, so in its default mode it doesn't warn about sizeof (void). Extensions like this are permitted …

2011年6月23日 · The compiler doesn't know the size of the item(s) the void pointer is pointing to. You can cast the pointer to (char *) to do so. In gcc there is an extension which treats the size …

2009年3月20日 · ¹ In ECMAScript 5 and later, the global variable undefined is guaranteed to be undefined (ECMA-262 5th Ed., § 15.1.1.3), though it is still possible to have a variable inside …