'int' is enough for 'length' to migrate code from x86 to x64

[via Digitalmars-d]

On Tuesday, 25 November 2014 at 15:42:13 UTC, Kagamin wrote:
> Correctness is an emergent property - when behavior matches 
> expectation, so overflow has variable correctness in various 
> parts of the code.

I assume you are basically saying that Walter's view that 
matching C++ is more important than getting it right, because 
some people might expect C++ behaviour. Yet Ada chose a different 
path and is considered a better language with respect to 
correctness.

I think it is important to get the definitions consistent and 
sound so they are easy to reason about, both for users and 
implementors. So one should choose whether the type is primarily 
monotonic, with incorrect values "truncated into" modulo N, or if 
the type is primarily modular.

If addition is defined to be primarily monotonic it means you can 
optimize "if(x < x+1)…" into "if (true)…". If it is defined to be 
primarily modular, then you cannot.