Getting Started on Unix Variants

Index

  • 1Get Boost
  • 2The Boost Distribution
  • 3Header-Only Libraries
  • 4Build a Simple Program Using Boost

    • 4.1Errors and Warnings
  • 5Prepare to Use a Boost Library Binary

    • 5.1Easy Build and Install
    • 5.2Or, Build Custom Binaries

      • 5.2.1Install Boost.Build
      • 5.2.2Identify Your Toolset
      • 5.2.3Select a Build Directory
      • 5.2.4Invoke b2
    • 5.3Expected Build Output
    • 5.4In Case of Build Errors
  • 6Link Your Program to a Boost Library

    • 6.1Library Naming
    • 6.2Test Your Program
  • 7Conclusion and Further Resources

1Get Boost

The most reliable way to get a copy of Boost is to download a
distribution from SourceForge:

  1. Download boost_1_50_0.tar.bz2.

  2. In the directory where you want to put the Boost installation,
    execute

    tar --bzip2 -xf /path/to/boost_1_50_0.tar.bz2

Other Packages

RedHat, Debian, and other distribution packagers supply Boost
library packages, however you may need to adapt these
instructions if you use third-party packages, because their
creators usually choose to break Boost up into several packages,
reorganize the directory structure of the Boost distribution,
and/or rename the library binaries.1 If you have
any trouble, we suggest using an official Boost distribution
from SourceForge.

2The Boost Distribution

This is a sketch of the resulting directory structure:

boost_1_50_0/ .................The “boost root directory”
index.htm .........A copy of www.boost.org starts here
boost/ .........................All Boost Header files

libs/ ............Tests, .cpps, docs, etc., by library
index.html ........Library documentation starts here
algorithm/
any/
array/
…more libraries…
status/ .........................Boost-wide test suite
tools/ ...........Utilities, e.g. Boost.Build, quickbook, bcp
more/ ..........................Policy documents, etc.
doc/ ...............A subset of all Boost library docs

Header Organization

The organization of Boost library headers isn't entirely uniform,
but most libraries follow a few patterns:

  • Some older libraries and most very small libraries place all
    public headers directly into boost/.

  • Most libraries' public headers live in a subdirectory of
    boost/, named after the library. For example, you'll find
    the Python library's def.hpp header in

    boost/python/def.hpp.

  • Some libraries have an “aggregate header” in boost/ that
    #includes all of the library's other headers. For
    example, Boost.Python's aggregate header is

    boost/python.hpp.

  • Most libraries place private headers in a subdirectory called
    detail/, or aux_/. Don't expect to find
    anything you can use in these directories.

It's important to note the following:

  1. The path to the boost root directory (often /usr/local/boost_1_50_0) is
    sometimes referred to as $BOOST_ROOT in documentation and
    mailing lists .

  2. To compile anything in Boost, you need a directory containing
    the boost/ subdirectory in your #include path.

  3. Since all of Boost's header files have the .hpp extension,
    and live in the boost/ subdirectory of the boost root, your
    Boost #include directives will look like:

    #include <boost/whatever.hpp>

    or

    #include "boost/whatever.hpp"

    depending on your preference regarding the use of angle bracket
    includes.

  4. Don't be distracted by the doc/ subdirectory; it only
    contains a subset of the Boost documentation. Start with
    libs/index.html if you're looking for the whole enchilada.

3Header-Only Libraries

The first thing many people want to know is, “how do I build
Boost?” The good news is that often, there's nothing to build.

Nothing to Build?

Most Boost libraries are header-only: they consist entirely
of header files containing templates and inline functions, and
require no separately-compiled library binaries or special
treatment when linking.

The only Boost libraries that must be built separately are:

  • Boost.Filesystem
  • Boost.GraphParallel
  • Boost.IOStreams
  • Boost.MPI
  • Boost.ProgramOptions
  • Boost.Python (see the Boost.Python build documentation
    before building and installing it)
  • Boost.Regex
  • Boost.Serialization
  • Boost.Signals
  • Boost.System
  • Boost.Thread
  • Boost.Wave

A few libraries have optional separately-compiled binaries:

  • Boost.DateTime has a binary component that is only needed if
    you're using its to_string/from_string or serialization
    features, or if you're targeting Visual C++ 6.x or Borland.
  • Boost.Graph also has a binary component that is only needed if
    you intend to parse GraphViz files.
  • Boost.Math has binary components for the TR1 and C99
    cmath functions.
  • Boost.Random has a binary component which is only needed if
    you're using random_device.
  • Boost.Test can be used in “header-only” or “separately compiled”
    mode, although separate compilation is recommended for serious
    use    .

4Build a Simple Program Using Boost

To keep things simple, let's start by using a header-only library.
The following program reads a sequence of integers from standard
input, uses Boost.Lambda to multiply each number by three, and
writes them to standard output:

#include <boost/lambda/lambda.hpp>
#include <iostream>
#include <iterator>
#include <algorithm>
int main()
{
using namespace boost::lambda;
typedef std::istream_iterator<int> in;
std::for_each(
in(std::cin), in(), std::cout << (_1 * 3) << " " );
}

Copy the text of this program into a file called example.cpp.

Now, in the directory where you saved example.cpp, issue the
following command:

c++ -I path/to/boost_1_50_0 example.cpp -o example

To test the result, type:

echo 1 2 3 | ./example

4.1Errors and Warnings

Don't be alarmed if you see compiler warnings originating in Boost
headers. We try to eliminate them, but doing so isn't always
practical.3 Errors are another matter. If you're
seeing compilation errors at this point in the tutorial, check to
be sure you've copied the example program correctly and that you've
correctly identified the Boost root directory.

5Prepare to Use a Boost Library Binary

If you want to use any of the separately-compiled Boost libraries,
you'll need to acquire library binaries.

5.1Easy Build and Install

Issue the following commands in the shell (don't type $; that
represents the shell's prompt):

$ cd path/to/boost_1_50_0
$ ./bootstrap.sh --help

Select your configuration options and invoke ./bootstrap.sh again
without the --help option. Unless you have write permission in
your system's /usr/local/ directory, you'll probably want to at
least use

$ ./bootstrap.sh --prefix=path/to/installation/prefix

to install somewhere else. Also, consider using the
--show-libraries and --with-libraries=library-name-list options to limit the
long wait you'll experience if you build everything. Finally,

$ ./b2 install

will leave Boost binaries in the lib/ subdirectory of your
installation prefix. You will also find a copy of the Boost
headers in the include/ subdirectory of the installation
prefix, so you can henceforth use that directory as an #include
path in place of the Boost root directory.

skip to the next step

5.2Or, Build Custom Binaries

If you're using a compiler other than your system's default, you'll
need to use Boost.Build to create binaries.

You'll also
use this method if you need a nonstandard build variant (see the
Boost.Build documentation for more details).

Boost.CMake

There is also an experimental CMake build for boost, supported and distributed
separately. See the Boost.CMake wiki page for more information.

5.2.1Install Boost.Build

Boost.Build is a text-based system for developing, testing, and
installing software. First, you'll need to build and
install it. To do this:

  1. Go to the directory tools/build/v2/.
  2. Run bootstrap.sh
  3. Run b2 install --prefix=PREFIX where PREFIX is
    the directory where you want Boost.Build to be installed
  4. Add PREFIX/bin to your PATH environment variable.

5.2.2Identify Your Toolset

First, find the toolset corresponding to your compiler in the
following table (an up-to-date list is always available in the
Boost.Build documentation).

Note

If you previously chose a toolset for the purposes of
building b2, you should assume it won't work and instead
choose newly from the table below.

Toolset
Name		 Vendor Notes
acc Hewlett Packard Only very recent versions are
known to work well with Boost
borland Borland
como Comeau Computing Using this toolset may
require configuring another
toolset to act as its backend
darwin Apple Computer Apple's version of the GCC
toolchain with support for
Darwin and MacOS X features
such as frameworks.
gcc The Gnu Project Includes support for Cygwin
and MinGW compilers.
hp_cxx Hewlett Packard Targeted at the Tru64
operating system.
intel Intel
msvc Microsoft
sun Sun Only very recent versions are
known to work well with
Boost.
vacpp IBM The VisualAge C++ compiler.

If you have multiple versions of a particular compiler installed,
you can append the version number to the toolset name, preceded by
a hyphen, e.g. intel-9.0 or
borland-5.4.3.

5.2.3Select a Build Directory

Boost.Build will place all intermediate files it generates while
building into the build directory. If your Boost root
directory is writable, this step isn't strictly necessary: by
default Boost.Build will create a bin.v2/ subdirectory for that
purpose in your current working directory.

5.2.4Invoke b2

Change your current directory to the Boost root directory and
invoke b2 as follows:

b2 --build-dir=build-directory toolset=toolset-name  stage

For a complete description of these and other invocation options,
please see the Boost.Build documentation.

For example, your session might look like this:

$ cd ~/boost_1_50_0
$ b2 --build-dir=/tmp/build-boost toolset=gcc stage

That will build static and shared non-debug multi-threaded variants of the libraries. To build all variants, pass the additional option, “--build-type=complete”.

Building the special stage target places Boost
library binaries in the stage/lib/ subdirectory of
the Boost tree. To use a different directory pass the
--stagedir=directory option to b2.

Note

b2 is case-sensitive; it is important that all the
parts shown in bold type above be entirely lower-case.

For a description of other options you can pass when invoking
b2, type:

b2 --help

In particular, to limit the amount of time spent building, you may
be interested in:

  • reviewing the list of library names with --show-libraries
  • limiting which libraries get built with the --with-library-name or --without-library-name options
  • choosing a specific build variant by adding release or
    debug to the command line.

Note

Boost.Build can produce a great deal of output, which can
make it easy to miss problems. If you want to make sure
everything is went well, you might redirect the output into a
file by appending “>build.log 2>&1” to your command line.

5.3Expected Build Output

During the process of building Boost libraries, you can expect to
see some messages printed on the console. These may include

  • Notices about Boost library configuration—for example, the Regex
    library outputs a message about ICU when built without Unicode
    support, and the Python library may be skipped without error (but
    with a notice) if you don't have Python installed.

  • Messages from the build tool that report the number of targets
    that were built or skipped. Don't be surprised if those numbers
    don't make any sense to you; there are many targets per library.

  • Build action messages describing what the tool is doing, which
    look something like:

    toolset-name.c++ long/path/to/file/being/built

  • Compiler warnings.

5.4In Case of Build Errors

The only error messages you see when building Boost—if any—should
be related to the IOStreams library's support of zip and bzip2
formats as described here. Install the relevant development
packages for libz and libbz2 if you need those features. Other
errors when building Boost libraries are cause for concern.

If it seems like the build system can't find your compiler and/or
linker, consider setting up a user-config.jam file as described
here. If that isn't your problem or the user-config.jam file
doesn't work for you, please address questions about configuring Boost
for your compiler to the Boost.Build mailing list.

7Conclusion and Further Resources

This concludes your introduction to Boost and to integrating it
with your programs. As you start using Boost in earnest, there are
surely a few additional points you'll wish we had covered. One day
we may have a “Book 2 in the Getting Started series” that addresses
them. Until then, we suggest you pursue the following resources.
If you can't find what you need, or there's anything we can do to
make this document clearer, please post it to the Boost Users'
mailing list.

  • Boost.Build reference manual
  • Boost Users' mailing list
  • Boost.Build mailing list
  • Index of all Boost library documentation

Onward

Good luck, and have fun!

—the Boost Developers

[1] If developers of Boost packages would like to work
with us to make sure these instructions can be used with their
packages, we'd be glad to help. Please make your interest known
to the Boost developers' list.
[2] That option is a dash followed by a lowercase “L”
character, which looks very much like a numeral 1 in some fonts.
[3] Remember that warnings are specific to each compiler
implementation. The developer of a given Boost library might
not have access to your compiler. Also, some warnings are
extremely difficult to eliminate in generic code, to the point
where it's not worth the trouble. Finally, some compilers don't
have any source code mechanism for suppressing warnings.
[4] This convention distinguishes the static version of
a Boost library from the import library for an
identically-configured Boost DLL, which would otherwise have the
same name.
[5] These libraries were compiled without optimization
or inlining, with full debug symbols enabled, and without
NDEBUG #defined. Although it's true that sometimes
these choices don't affect binary compatibility with other
compiled code, you can't count on that with Boost libraries.
[6] This feature of STLPort is deprecated because it's
impossible to make it work transparently to the user; we don't
recommend it.
Key Use this library when: Boost.Build option
s linking statically to the C++ standard library and compiler runtime support
libraries.		 runtime-link=static
g using debug versions of the standard and runtime support libraries. runtime-debugging=on
y using a special debug build of Python. python-debugging=on
d building a debug version of your code.5 variant=debug
p using the STLPort standard library rather than the default one supplied with
your compiler.		 stdlib=stlport

Good luck, and have fun!

—the Boost Developers

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