Besides that function pointers can only point to static (nested) functions, is there any difference?

Sean

Sean Kelly wrote:

> Besides that function pointers can only point to static (nested) functions, is there any difference?

Welcome to OOP.

A static function is one that is a member of a class, but operates on the class itself, not on an object of the class.  Just as a static variable belongs to the class, rather than to each object of the class.  Hence there is no concept of 'this' in a static function.

	class Qwert {
		static int yuiop;
		int asdfg;

		static void hjkl() {
			printf("%d\n", yuiop);	// valid
			printf("%d\n", asdfg);	// invalid
		}

		void zxcvb() {
			printf("%d\n", yuiop);	// valid
			printf("%d\n", asdfg);	// also valid
		}

		static void nm() {
			hjkl();		// valid
			zxcvb();	// invalid
		}
	}

If you're nesting functions within functions, then the same applies. Here, the concept of 'object' is more or less replaced by 'stack frame', corresponding to a call to the enclosing function.

Stewart.

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Stewart Gordon wrote:
> 
> If you're nesting functions within functions, then the same applies. Here, the concept of 'object' is more or less replaced by 'stack frame', corresponding to a call to the enclosing function.

Ah, that was what I was missing.  As C++ doesn't support nested functions I wasn't sure how the keyword applied outside of the class context.  Just to clarify, how does the classic definition of "static" as it applies to global symbols in C operate in D?  If I declare a global variable or free function static, does it have any effect at all?  Can I still assume that a D module and its imports rougly corresponds to a translation unit and that global statics will follow the classic visibility rules?

Sean

Sean Kelly wrote:
> Stewart Gordon wrote:
> 
>>
>> If you're nesting functions within functions, then the same applies. Here, the concept of 'object' is more or less replaced by 'stack frame', corresponding to a call to the enclosing function.
> 
> 
> Ah, that was what I was missing.  As C++ doesn't support nested functions I wasn't sure how the keyword applied outside of the class context.  Just to clarify, how does the classic definition of "static" as it applies to global symbols in C operate in D?  If I declare a global variable or free function static, does it have any effect at all?  Can I still assume that a D module and its imports rougly corresponds to a translation unit and that global statics will follow the classic visibility rules?

The C concept of static certainly does not apply to D.  If you want a symbol to be local to the module, use the 'private' access modifier instead.

I think static is ignored in the global scope. (I'm not sure if it ought to be a syntax error, as it might be handy in the case of mixins)

 -- andy