Phobos for Review: std.buffer.scopebuffer

[Walter Bright]

On 2/7/2014 1:13 AM, Walter Bright wrote:
> On 2/7/2014 12:46 AM, Brad Anderson wrote:
>> Why not just stick the stack array in ScopeBuffer itself (the
>> size could be a template parameter)?
>
> 1. It's set up to fit into two registers on 64 bit code. This means it can be
> passed/returned from functions in registers. When I used this in my own code,
> high speed was the top priority, and this made a difference.
>
> 2. It needs to avoid the default initialization of the array, because it's both
> unnecessary and it kills the speed. Currently, this
> cannot be avoided for part of a struct.
>
> 3. I wanted it to be usable for any block of memory the user wished to dedicate
> to be a buffer.
>
> 4. Having an internal reference like that would mean a postblit is required for
> copying/moving the range, another source of speed degradation.

5. Every instantiation that only differs by the buffer size would generate a 
separate set of code. Having the buffer size passed into the constructor means 
only one instance is generated per type.