std.allocator issues

[Steven Schveighoffer via Digitalmars-d]

On 2/19/16 9:21 PM, Steven Schveighoffer wrote:
> I'm trying to use the std.experimental.allocator API more in my new io
> library, and I'm having a few stumbling points:

Another thought:

Allocators return void[] when requesting allocations, reallocations, 
etc. For C malloc, the assumption must be that what you requested is 
what you got, because the actual block size isn't given. However, for GC 
(and I assume other allocators), we have mechanisms to know upon 
allocation the amount of data received.

I would assume since we are returning both pointer and length, it would 
be possible for an allocator to return more data than requested (why 
waste it?). But it appears that the GC allocator just returns the amount 
of data requested, even though it could return the extra data that was 
received.

Should the API assumptions allow returning more data than requested? It 
means code has to be wary of this, but creating a wrapper allocator that 
truncates the data would be trivial, no?

I want to write some PRs to fix this, but I'm unclear what is expected.

-Steve