[section Performance]

[#BOOST_METAPARSE_STRING_benchmark]
[section Benchmarks of BOOST_METAPARSE_STRING]

Measurements related to the performance of the
[link BOOST_METAPARSE_STRING `BOOST_METAPARSE_STRING`] macro.

[section Increasing string length]

[include length128_gcc_4.8.5.qbk]

[endsect]

[section Increasing number of strings]

[include number_gcc_4.8.5.qbk]

[endsect]

[section Increasing string length limit]

[include max_length_gcc_4.8.5.qbk]

[endsect]

[endsect]

[section Measuring printf]

Parsers work at compile-time, thus their performance affects compilation speed.
This section shows measurements of compilation time using Metaparse. The
measurements were done on a Linux laptop with an 1.6 GHz Atom processor and 1 GB
memory. The measurements were done using GCC 4.6.1 with `-std=c++0x` and no
optimisation. Compilation speed was measured using the `time` utility.

To measure a non-trivial parser, the `printf` example program were used for
measurements. Here is a list of the `printf` calls and their compilation speed
(`user` output of `time`):

[table Printf compilation speed
  [[type-safe `printf` call] [Compilation speed (s)]]

  [[No compile-time parsing (just the includes and an empty `main`)]         [3.51]]
  [[`printf<BOOST_METAPARSE_STRING("%f")>(1.0)`]                             [4.95]]
  [[`printf<BOOST_METAPARSE_STRING("%f%f")>(1.0, 2.0)`]                      [5.26]]
  [[`printf<BOOST_METAPARSE_STRING("%f%f%f")>(1.0, 2.0, 3.0)`]               [5.50]]
  [[`printf<BOOST_METAPARSE_STRING("%f%f%f%f")>(1.0, 2.0, 3.0, 4.0)`]        [5.82]]
  [[`printf<BOOST_METAPARSE_STRING("%f%f%f%f%f")>(1.0, 2.0, 3.0, 4.0, 5.0)`] [6.07]]
]

[endsect]

[section Further measurements]

Further measurements can be found in the following paper:

Zoltán Porkoláb, Ábel Sinkovics: [br]
[*Domain-specific Language Integration with Compile-time Parser Generator Library] [br]
In Eelco Visser, Jaakko Järvi, editors, Proceedings of the ninth
international conference on Generative programming and component
engineering (GPCE 2010). ACM, October 2010, pp. 137-146.

[endsect]

[endsect]

