Required Reading: "How Non-Member Functions Improve Encapsulation"

[H. S. Teoh]

On Wed, Oct 25, 2017 at 03:19:23PM -0700, Walter Bright via Digitalmars-d wrote:
> for core D devs.
> 
> "How Non-Member Functions Improve Encapsulation" by Scott Meyers
> 
> http://www.drdobbs.com/cpp/how-non-member-functions-improve-encapsu/184401197
> 
> Note that I'm as guilty as anyone for not understanding or following
> these guidelines. I expect we can do much better.

Page 2 of this article is essentially another reason why UFCS in D
totally rawkz.  In D, we can take Scott's advice *without* suffering
from syntactic inconsistency between member and non-member functions:

	// C++:
	class C {
		public:
			int method();
		private: ...
	};

	int anotherMethod(C &c, ...);

	C c;
	c.method();
	anotherMethod(c);	// <-- syntactic inconsistency


	// D:
	class C {
		public int method();
		private: ...
	}
	int anotherMethod(C c, ...);

	C c;
	c.method();
	c.anotherMethod();	// <-- Uniform syntax FTW!

Arguably, this means in D encapsulation is even better than in C++: the
user doesn't even have to care whether a function is a member or not.
The same syntax does the Right Thing(tm).

Furthermore, if the class implementation changes in a drastic way that
makes it possible to make a current member function a non-member, we can
do it in D without needing to touch any client code at all!


T

-- 
Кто везде - тот нигде.