Re: [boost] [container] New container: why is everybody silent?

Christopher Kormanyos writes:

Hi Alex,

I tested the container with a floating-point benchmark that also performs numerous sequential operations on iterators ranging from [begin, end).

Here is my report and the interpretation of the report below the report:

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I found many warnings in both GCC as well as VC:

I stripped the implementation: * I removed all exception handling and asserts.

I identified the container uses in the benchmark: * Create two containers. * One container has 4 floats, the other has 5 floats.

Do in a loop about 10 times the following: * On each container apply std::accumulate with std::multiplies. * On each container apply std::for_each with element incrementation. * Do the normal floating-point operations and loop management.

I use a custom allocator with 512 byte pool: * typedef util::ring_allocator<T> allocator_type;

I use either btree_seq or std::vector: * typedef btree_seq container_type; * typedef std::vector container_type;

I perform the numerical correctness analysis: * Run on PC with VS2012.  Result OK. * Run on ARM A8 with GCC. Result OK.

I perform the size analysis on the ARM(R): * using neither     :  7344 byte * using std::vector :  8928 byte, delta = 1584 * using btree_seq   : 15968 byte, delta = 8624

I perform the runtime analysis on the ARM(R): * using std::vector : 4.4 microseconds * using btree_seq   : 5.3 microseconds

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Interpretation:

The btree_seq obtains the correct result and can be used on a PC as well as microcontroller with a custom allocator. This is very positive!

The btree_seq creates much more code than the corresponding use of std::vector. In addition, btree_seq runs significantly slower than std::vector in this particular benchmark.

The code could be potentially cleaned up significantly. For this, build at very high warning levels and eliminate all warnings.

As mentioned earlier, some C++11 awareness might be mandatory. An awareness of move construction, nullptr where appropriate, and construction / equating with std::initializer_list. Boost has C++11 compiler switches for these and more C++11 features.

If you would like to see the code of the benchmark, it is available in the public domain.

I encourage you to keep going.

Cheers Chris

Hi, Chris! 1) Thank you for spending some time to test my container. 2) Performance. Yes, for iterative and random-access the vector is slightly better (but only slightly, I'm also encouraged by 5.3 : 4.2 score). Vector is champion for these operations, and probably nobody can outperform it. But as soon as insertions/deletions are necessary, my container can outperform. 3) Real app. Are you writing the real app for microcontroller now? If you use insertions/deletions, especially random ones, my container can significantly outperform. Even if you just use push_back, my thing can slightly outperform. However, if you use iterative-access, vector wins, but not too much. I suggest you to try to use my thing in the real app. 4) Benchmark - can you provide a link? 5) C++11 - fully accepted. I'll deal with it soon. 6) Warnings - fully accepted. Best regards, and thank you again Aleksandr