DIP 1015--Deprecation of Implicit Conversion of Int. & Char. Literals to bool--Formal Assement

[H. S. Teoh]

On Tue, Nov 13, 2018 at 02:12:30AM +0000, 12345swordy via Digitalmars-d-announce wrote:
> On Monday, 12 November 2018 at 21:38:27 UTC, Walter Bright wrote:
[...]
> > The underlying issue is is bool a one bit integer type, or something
> > special? D defines it as a one bit integer type, fitting it into the
> > other integer types using exactly the same rules.
> > 
> > If it is to be a special type with special rules, what about the
> > other integer types? D has a lot of basic types :-)
> 
> Ok, you don't want to introduce special rules for integers, and that
> understandable.
>
> However there needs be a tool for the programmer to prevent unwanted
> implicit conversation when it comes to other users passing values to
> their public overload functions.(Unless there is already a zero cost
> abstraction that we are not aware of).
[...]

This discussion makes me want to create a custom bool type that does not
allow implicit conversion. Something like:

	struct Boolean {
		private bool impl;
		static Boolean True = Boolean(1);
		static Boolean False = Boolean(0);

		// For if(Boolean b)
		opCast(T : bool)() { return impl; }

		...
	}

Unfortunately, it wouldn't quite work because there's no way for
built-in comparisons to convert to Boolean instead of bool. So you'd
have to manually surround everything with Boolean(...), which is a
severe usability handicap.


T

-- 
People tell me that I'm skeptical, but I don't believe them.