Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
This section explains how to setup a system to use this library.
Programmers should have enough knowledge to use this library after reading the Introduction, Getting Started, and Tutorial sections. The Advanced Topics and Reference sections can be consulted at a later point to gain a more advanced knowledge of the library. All the other sections of this documentation can be considered optional.
Some footnotes are marked by the word "Rationale". They explain reasons behind decisions made during the design and implementation of this library.
In most of the examples presented in this documentation, the Boost.Detail/LightweightTest
(boost/detail/lightweight_test.hpp) macro BOOST_TEST is used to check correctness
conditions. The BOOST_TEST
macro is conceptually similar to assert
but a failure of the checked condition does not abort the program, instead
it makes boost::report_errors return a non-zero program
exit code. [3]
The implementation of this library uses preprocessor and template meta-programming (as supported by Boost.Preprocessor and Boost.MPL), templates with partial specializations and function pointers (similarly to Boost.Function), and automatic type deduction (as supported by Boost.Typeof). The authors originally developed and tested the library on:
-std=c++0x)
on Cygwin.
See the library regressions test results for detailed information on supported compilers and platforms.
This library is composed of header files only. Therefore there is no pre-compiled
object file which needs to be installed or linked. Programmers can simply
instruct the C++ compiler where to find the library header files (-I option
for GCC, /I
option for MSVC, etc) and they can start compiling code using this library.
The library implementation uses Boost.Typeof
to automatically deduce the types of bound variables (see the Tutorial
section). In order to compile code in type-of emulation mode, all types should
be properly registered using BOOST_TYPEOF_REGISTER_TYPE
and BOOST_TYPEOF_REGISTER_TEMPLATE,
or appropriate Boost.Typeof
headers should be included (see the source code of most examples presented
in this documentation).
The followings are part of the library private API, they are not documented, and they should not be directly used by programmers: [4]
boost/local_function/aux_/
or boost/local_function/detail/ directory (these header
files should not be directly included by programmers).
boost::local_function::aux
or boost::local_function::detail namespace.
boost_local_function_aux_... or boost_local_function_detail_... (regardless of its namespace).
BOOST_LOCAL_FUNCTION_AUX_... or BOOST_LOCAL_FUNCTION_DETAIL_... (regardless of its namespace).
Some of the library behaviour can be changed at compile-time by defining
special configuration macros. If a configuration macro
is left undefined, the library will use an appropriate default value for
it. All configuration macros are defined in the header file boost/local_function/config.hpp.
It is strongly recommended not to change the library configuration macro
definitions unless strictly necessary.
[3] Rationale. Using Boost.Detail/LightweightTest allows to add the examples to the library regression tests so to make sure that they always compile and run correctly.
[4]
Rationale. This library concatenates symbols
specified by the programmers (e.g., the local function name) with other
symbols (e.g., special prefixes or file line numbers) to make internal
symbols with unique names to avoid name clashes. These symbols are separated
by the letter "X"
when they are concatenated so they read more easily during debugging (the
underscore character "_"
could not be used instead of the letter "X"
because if the original symbols already contained a leading or trailing
underscore, the concatenation could result in a symbol with double underscores
"__" which is
reserved by the C++ standard). The "aux" symbols are private
to this library while the "detail" symbols may be used within
Boost by other libraries but they are still not part of this library public
API.