Ranges:
-------

The 'typedef' declaration could also be used to introduce new numeric types with user-defined ranges:

typedef:
typedef decl RangeDecl

RangeDecl:
( Min .. Max )

Example:
typedef int RadarRange(100 .. 20000) = 500;


The .min and '.max' properties of the new type will be adjusted accordingly by the compiler.


Static property 'valid':
------------------------

A type (primitive/enum/struct/class/array) could have a static property 'valid' which returns 'true' when the content of the variable that it is applied to is valid.

Example:

RadarRange currentRadarRange;
bool isValidRange = currentRadarRange.valid;

The .valid static property would be useful for checking at run-time if a value is valid (within range/accepted values). The .valid check would propagate in composite type's members, thus allowing for checking whole structs/classes/arrays if they have valid content.

It would save the programmer lots of work from checking if an enumerated value has a valid content.


Rationale:
----------

D could be used in place of ADA for defense applications (I could certainly propose it to my boss if it had the above-mentioned capabilities!).

I actually proposed an idea similar to this many months ago.  My proposed syntax was rather different, but the concept was essentially the same.  I had it set to look something like:

------------------------------
typedef int myint {
  init : -1,
  min  : -3,
  max  : int.max
}
------------------------------

I'd also proposed the idea of adding new properties to the typedef'd type.  Maybe your proposal will get more attention than mine.

-C. Sauls
-Invironz