Get size of mem to free by free

[H.Loom via Digitalmars-d-learn]

On Friday, 5 August 2016 at 21:07:02 UTC, H.Loom wrote:
> On Friday, 5 August 2016 at 20:54:59 UTC, Mark "J" Twain wrote:
>> On Friday, 5 August 2016 at 20:43:12 UTC, H.Loom wrote:
>>> On Friday, 5 August 2016 at 19:55:22 UTC, Mark "J" Twain 
>>> wrote:
>>>> [...]
>>>
>>> You can wrap the C memory allocations functions with a 
>>> version identifier, e.g
>>>
>>>
>>> version(stat)
>>> {
>>>     __gshared size_t[size_t] sizes;
>>> }
>>>
>>> version(stat)
>>> {
>>>     auto malloc(size_t size)
>>>     {
>>>         auto result = std.c.stdlib.malloc(size);
>>>         sizes[result] = size;
>>>         return result;
>>>     }
>>> }
>>> else alias malloc = std.c.stdlib.malloc;
>>>
>>> version(stat)
>>> {
>>>     void free(void* ptr)
>>>     {
>>>         std.c.stdlib.free(ptr);
>>>         sizes.remove(ptr);
>>>     }
>>> }
>>> else alias free = std.c.stdlib.free;
>>>
>>>
>>> that a bit a DIY but this would work.
>>
>> Yeah, I ended up just storing the sizes in the ptr on malloc. 
>> Essentially the same but I don't have to keep a global around 
>> and deal with that.
>
> you cannot get rid of a global variable to store the sizes. 
> Even if it's hidden in an API you didn't write, in which case 
> it's just hidden.
>
> Have you looked at experimental allocators ?

More especially 
https://github.com/dlang/phobos/blob/master/std/experimental/allocator/building_blocks/stats_collector.d

instead of using malloc/free you can use Mallocator (this is the 
same).

Maybe that StatsCollector!Mallocator == win for you.