thoughts on immutability in D

[Walter Bright]

On 9/23/2011 4:13 PM, Jonathan M Davis wrote:
> But while C++'s const is not as good as D's const, it's still very worthwhile
> IMHO.

To me it's like buffer overflows. 99% of C/C++ code doesn't have buffer 
overflows, and is perfectly reliable. But if someone hands you a 1,000,000 line 
program and asks "ensure there are no buffer overflows" what are you going to 
do? What are you going to do when Junior Programmer makes a patch to your 
perfectly correct C/C++ code base, and now it has a subtle overflow bug? Start 
all over with the review process?

This is not an idle question, as a major focus of C static analysis tools is to 
detect buffer overflows, and people spend a lot of effort & money on them.

Faith based programming works in the small, but programs grow ever larger in 
size and complexity. Switching from faith to static guarantees is a much more 
scalable technique.

And where C++ const is really, really useless is when it comes to multithreaded 
programming.