Vision for the D language - stabilizing complexity?

[Walter Bright via Digitalmars-d]

On 7/15/2016 12:55 PM, Jack Stouffer wrote:
> On Friday, 15 July 2016 at 19:06:15 UTC, Walter Bright wrote:
>> 4. making use of asserts to provide information to the optimizer
>
> Do dmd/ldc/gdc actually do this?

dmd doesn't. I don't know about other compilers.

The point is it's possible because C++ doesn't have asserts. C++ has an assert 
macro, defined to be the same as in C. The definition of assert in C is such 
that it is turned on/off with the NDEBUG macro, meaning that when it is off, the 
compiler CANNOT derive any semantic information from it, because it effectively 
vanishes from the code.

In contrast, assert in D is a keyword and has a semantic production. Even if 
generating code for the assert is disabled with the -release switch, the 
semantics of it remain and are available to the optimizer.

C++ didn't repeat that mistake with 'static_assert' (another feature copied from 
D), but static assert doesn't help the optimizer.