checkedint call removal

[bearophile via Digitalmars-d]

> a way for x and y (that are of the library-defined type SInt) 
> to keep the value range of an ubyte.

Such management of value ranges by library code could also allow 
to modify the implementation of iota to compile this:


void main() {
     import std.range, std.algorithm;
     auto result = iota(20).map!(i => char(i + 'a'));
}


That mimics with library code this program that today compiles 
(thanks to various improvements in foreach range handling:

void main() {
     foreach (immutable i; 0 .. 20)
         char c = char(i + 'a');
}


You can probably special-case iota() in the compiler, to allow 
the first program (because in D the x..y is not first class, 
unfortunately), but if you offer more generic tools usable by 
library code you can use them in many other situations.

Bye,
bearophile