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Mention a POSIX extension of printf.

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Victor Zverovich 2012-12-09 10:09:15 -08:00
parent 280ea8b5c5
commit cb458293a3
1 changed files with 19 additions and 17 deletions
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36
README.rst
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@ -39,12 +39,14 @@ Printf
~~~~~~
The good thing about printf is that it is very fast and readily available
being the part of the C standard library. The main drawbacks are that it
doesn't support user-defined types, it is unsafe although the latter
problem is mostly solved with `__attribute__ ((format (printf, ...))
<http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html>`__ in GCC
and it doesn't support positional arguments required for `i18n
<http://en.wikipedia.org/wiki/Internationalization_and_localization>`__.
being the part of the C standard library. The main drawback is that it
doesn't support user-defined types. Printf also has safety issues although
they are mostly solved with `__attribute__ ((format (printf, ...))
<http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html>`__ in GCC.
There is a POSIX extension that adds positional arguments required for
`i18n <http://en.wikipedia.org/wiki/Internationalization_and_localization>`__
to printf but it is not a part of C99 and may not be available on some
platforms.
IOStreams
~~~~~~~~~
@ -58,8 +60,8 @@ which is a lot of typing compared to printf::
printf("%.2f\n", 1.23456);
Matthew Wilson, the author of FastFormat referred to this situations with
IOStreams as "chevron hell".
As with printf, there is no chance to support i18n.
IOStreams as "chevron hell". IOStreams doesn't support positional arguments
by design.
The good part is that IOStreams supports user-defined types and is safe
although error reporting is awkward.
@ -69,10 +71,9 @@ Boost Format library
This is a very powerful library which supports both printf-like format
strings and positional arguments. The main its drawback is performance.
According to various benchmarks it is so slow that I wouldn't recommend
it for purposes other than occasional message reporting in small to medium
size projects that are not performance-critical. It also has excessive
build times and severe code bloat issues (see `Benchmarks`_).
According to various benchmarks it is much slower than other methods
considered here. Boost Format also has excessive build times and severe
code bloat issues (see `Benchmarks`_).
FastFormat
~~~~~~~~~~
@ -203,8 +204,9 @@ Acknowledgments
The benchmark section of this readme file and the performance tests are taken
from the excellent `tinyformat <https://github.com/c42f/tinyformat>`__ library
written by Chris Foster. boost::format is acknowledged transitively since
it had some influence on tinyformat. Some ideas used in the implementation
are borrowed from `Loki <http://loki-lib.sourceforge.net/>`__ SafeFormat and
`Diagnostic API <http://clang.llvm.org/doxygen/classclang_1_1Diagnostic.html>`__
in `Clang <http://clang.llvm.org/>`__.
written by Chris Foster. Boost Format library is acknowledged transitively
since it had some influence on tinyformat.
Some ideas used in the implementation are borrowed from `Loki
<http://loki-lib.sourceforge.net/>`__ SafeFormat and `Diagnostic API
<http://clang.llvm.org/doxygen/classclang_1_1Diagnostic.html>`__ in
`Clang <http://clang.llvm.org/>`__.