[LLVMdev] Forward: Discussion about custom memory allocators for STL

[Kenneth Boyd]

Roman Levenstein wrote:
> Hi,
>
> There is a discussion thread on llvm-commits list about a possibility of using custom memory allocators for STL to improve the performance and reduce the memory pressure of STL containers, e.g. std::set.
> I thought that this discussion may be interesting for a wider audience and therefore I re-post the messages on llvm-dev as well.
>
> It would be interesting to hear what others think about 
>  - custom allocators, 
>   
Only as a build option, and must include performance comparisons against 
the default allocator in automated testing.
>  - reasons for current inefficiency of many STL containers on Evan's/Chris configs and 
>  - possibility of using 3rd party libs like Boost (or their parts) in LLVM
>   
I'd consider forking from Boost at least:
* static asserts in conjunction with the type traits library and 
std::numeric_limits
* concept_check
* the enable_if library allowing conditional definition of templates, 
again in conjunction with the type traits library and std:::numeric_limits.

I believe GCC uses a forked version of Boost for the first two points, 
in its STL.  (At least, the comments suggest this.)

Kenneth Boyd