PhobosWatch: manifest => enum

[Derek Parnell]

On Sat, 29 Dec 2007 14:43:28 -0800, Walter Bright wrote:

> Jérôme M. Berger wrote:
>> Walter Bright wrote:
>>> Yes, that could be done, but we're still stymied by the problem that we
>>> are unable to declare a constant of type 'int', only 'const(int)'.
>> 
>> 	I don't see any situation in which we would need a constant of type
>> "int" instead of "const (int)" or "invariant (int)". After all, if
>> it is a *constant*, it should be either "const" or "invariant", no?
> 
> Consider the following:
> 
> 	const int X = 3;
> 	auto i = X;
> 	i = 4;		// error, i is const
> 
> Essentially, it would make type inference far less useful.

I think I'm confused here. Are you saying Walter, that in this example, 'i'
would NOT be const?

My simple reasoning goes like this ...

 const int X = 3;

declares that X is a 'const int' data type.

 auto i = X;

declares that 'i' automatically takes on the data type of 'X', thus 'i' is
also a 'const int' and its initial (and only) value is the same as in 'X'.

  i = 4;

should be an error because i is immutable.


To have 'auto' strip off const should be an explicit thing. This would
enable us to have a better definition of APIs too, which is something you
want.

   mutable auto i = X;  // by way of example

-- 
Derek Parnell
Melbourne, Australia
skype: derek.j.parnell