Strict aliasing in D

[Walter Bright]

On 7/27/2013 1:57 AM, David Nadlinger wrote:
> On Saturday, 27 July 2013 at 06:58:04 UTC, Walter Bright wrote:
>> Although it isn't in the spec, D should be "strict aliasing". This is because:
>>
>> 1. it enables better code generation
>>
>> 2. there are ways, such as unions, to get the other aliasing that doesn't
>> break strict aliasing
>
> We need to carefully formalize this then, and quickly. The problem GCC, Clang
> and others are facing is that (as you are probably aware) 2. isn't guaranteed to
> work for type-casting pointers either by the specs, but people want to be able
> to do this nonetheless.
>
> Thus, they both accept pointer aliasing through union types, trying to optimize
> as much as possible while avoiding to break people's expectations and existing
> code. This is a very unfortunate situation for both compiler developers and
> users; just search for something like "gcc strict aliasing" on StackOverflow for
> examples.
>
> There is already quite a lot of D code out there that violates the C-style
> strict aliasing rules.

I agree. Want to do an enhancement request on bugzilla for it?