A howl on the wind…

(newer version from 2012-02-20, older std::map benchmarks for GNU g++ 4.3.2 and MSVC++ 2010 beta 2)

A performance comparison of the speed of operations on the various set implementations used in C++. There are 16383 unique elements across which 1000000 insert, lookup, iterate, and erase operations are performed.

And this time I’ve left the raw tick numbers and enabled table sorting so you can compare for yourself. Just be aware that the Linux and Windows numbers cannot be compared against each other.

Sources

• Containers: std::set, std::unordered_set, boost::unordered_set, sorted_vector, sorted_deque
• Ticks counted via cycle.h (local mirror)
• Source: speed-set-int.cpp and speed-set-string.cpp

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(There is also an opposite string-to-int performance test.)
(Updated 2011-02-05: Added a hand-made function as baseline; re-run all tests, and with new clang++ from svn)

A performance benchmark of which method is faster of converting an integer to an std::string. The goal is ending up with an std::string representation of the input integer.

The tested methods are:

• naive loop into a std::string
• sprintf() into a char[] buffer, then std::string(buffer)
• snprintf() into a char[] buffer, then std::string(buffer)
• sprintf() into &std::string[0], and .resize() to fit
• snprintf() into &std::string[0], and .resize() to fit
• output to a std::stringstream, then std::string = stream.str()
• as above, but reusing the stringstream object
• std::strstream(&string[0]) then .resize(stream.pcount())
• std::string = boost::lexical_cast<std::string>()
• Boost.Spirit.Karma generate into a char[] buffer, then std::string(buffer)

Source for the test is at speed-convert-int-to-string.cpp with cycle.h.

The compilers are Microsoft Visual C++ 2010 Express as VC10 with _SECURE_SCL disabled, GNU g++ 4.4.1, and clang++ from svn.

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