d3cf4d7224
2008-06-24 Benjamin Kosnik <bkoz@redhat.com> * doc/xml/manual/parallel_mode.xml: Clarify use of explicit parallel algorithms. * doc/xml/manual/using.xml: Markup fixes caught by validation check. * doc/xml/manual/test.xml: Remove empty para tags. * doc/html/*: Regenerate. From-SVN: r137085
1046 lines
49 KiB
XML
1046 lines
49 KiB
XML
<?xml version='1.0'?>
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<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"
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[ ]>
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<chapter id="manual.intro.using" xreflabel="Using">
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<?dbhtml filename="using.html"?>
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<title>Using</title>
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<sect1 id="manual.intro.using.lib" xreflabel="Lib">
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<title>Linking Library Binary Files</title>
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<para>
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If you only built a static library (libstdc++.a), or if you
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specified static linking, you don't have to worry about this.
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But if you built a shared library (libstdc++.so) and linked
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against it, then you will need to find that library when you run
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the executable.
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</para>
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<para>
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Methods vary for different platforms and different styles, but
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the usual ones are printed to the screen during installation.
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They include:
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</para>
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<itemizedlist>
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<listitem>
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<para>
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At runtime set LD_LIBRARY_PATH in your environment
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correctly, so that the shared library for libstdc++ can be
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found and loaded. Be certain that you understand all of the
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other implications and behavior of LD_LIBRARY_PATH first
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(few people do, and they get into trouble).
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</para>
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</listitem>
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<listitem>
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<para>
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Compile the path to find the library at runtime into the
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program. This can be done by passing certain options to
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g++, which will in turn pass them on to the linker. The
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exact format of the options is dependent on which linker you
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use:
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</para>
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<itemizedlist>
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<listitem>
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<para>
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GNU ld (default on Linux):<literal>-Wl,--rpath,<filename class="directory">destdir</filename>/lib</literal>
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</para>
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</listitem>
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<listitem>
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<para>
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IRIX ld:<literal>
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-Wl,-rpath,<filename class="directory">destdir</filename>/lib</literal>
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</para>
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</listitem>
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<listitem>
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<para>
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Solaris ld:<literal>-Wl,-R<filename class="directory">destdir</filename>/lib</literal>
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</para>
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</listitem>
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<listitem>
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<para>
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More...? Let us know!
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</para>
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</listitem>
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</itemizedlist>
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</listitem>
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</itemizedlist>
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<para>
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Use the <command>ldd</command> utility to show which library the
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system thinks it will get at runtime.
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</para>
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<para>
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A libstdc++.la file is also installed, for use with Libtool. If
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you use Libtool to create your executables, these details are
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taken care of for you.
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</para>
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</sect1>
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<sect1 id="manual.intro.using.headers" xreflabel="Headers">
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<title>Headers</title>
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<sect2 id="manual.intro.using.headers.all" xreflabel="Header Files">
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<title>Header Files</title>
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<para>
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The C++ standard specifies the entire set of header files that
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must be available to all hosted implementations. Actually, the
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word "files" is a misnomer, since the contents of the
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headers don't necessarily have to be in any kind of external
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file. The only rule is that when one <code>#include</code>'s a
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header, the contents of that header become available, no matter
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how.
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</para>
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<para>
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That said, in practice files are used.
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</para>
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<para>
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There are two main types of include files: header files related
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to a specific version of the ISO C++ standard (called Standard
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Headers), and all others (TR1, C++ ABI, and Extensions).
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</para>
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<para>
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Two dialects of standard headers are supported, corresponding to
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the 1998 standard as updated for 2003, and the draft of the
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upcoming 200x standard.
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</para>
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<para>
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C++98/03 include files. These are available in the default compilation mode, i.e. <code>-std=c++98</code> or <code>-std=gnu++98</code>.
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</para>
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<table frame='all'>
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<title>C++ 1998 Library Headers</title>
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<tgroup cols='5' align='left' colsep='1' rowsep='1'>
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<colspec colname='c1'></colspec>
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<colspec colname='c2'></colspec>
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<colspec colname='c3'></colspec>
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<colspec colname='c4'></colspec>
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<tbody>
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<row><entry><filename class="headerfile">algorithm</filename></entry><entry><filename class="headerfile">iomanip</filename></entry><entry><filename class="headerfile">list</filename></entry><entry><filename class="headerfile">ostream</filename></entry><entry><filename class="headerfile">streambuf</filename></entry></row>
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<row><entry><filename class="headerfile">bitset</filename></entry><entry><filename class="headerfile">ios</filename></entry><entry><filename class="headerfile">locale</filename></entry><entry><filename class="headerfile">queue</filename></entry><entry><filename class="headerfile">string</filename></entry></row>
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<row><entry><filename class="headerfile">complex</filename></entry><entry><filename class="headerfile">iosfwd</filename></entry><entry><filename class="headerfile">map</filename></entry><entry><filename class="headerfile">set</filename></entry><entry><filename class="headerfile">typeinfo</filename></entry></row>
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<row><entry><filename class="headerfile">deque</filename></entry><entry><filename class="headerfile">iostream</filename></entry><entry><filename class="headerfile">memory</filename></entry><entry><filename class="headerfile">sstream</filename></entry><entry><filename class="headerfile">utility</filename></entry></row>
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<row><entry><filename class="headerfile">exception</filename></entry><entry><filename class="headerfile">istream</filename></entry><entry><filename class="headerfile">new</filename></entry><entry><filename class="headerfile">stack</filename></entry><entry><filename class="headerfile">valarray</filename></entry></row>
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<row><entry><filename class="headerfile">fstream</filename></entry><entry><filename class="headerfile">iterator</filename></entry><entry><filename class="headerfile">numeric</filename></entry><entry><filename class="headerfile">stdexcept</filename></entry><entry><filename class="headerfile">vector</filename></entry></row>
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<row><entry><filename class="headerfile">functional</filename></entry><entry><filename class="headerfile">limits</filename></entry></row>
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</tbody>
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</tgroup>
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</table>
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<para></para>
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<table frame='all'>
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<title>C++ 1998 Library Headers for C Library Facilities</title>
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<tgroup cols='5' align='left' colsep='1' rowsep='1'>
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<colspec colname='c1'></colspec>
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<colspec colname='c2'></colspec>
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<colspec colname='c3'></colspec>
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<colspec colname='c4'></colspec>
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<tbody>
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<row><entry><filename class="headerfile">cassert</filename></entry><entry><filename class="headerfile">ciso646</filename></entry><entry><filename class="headerfile">csetjmp</filename></entry><entry><filename class="headerfile">cstdio</filename></entry><entry><filename class="headerfile">ctime</filename></entry></row>
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<row><entry><filename class="headerfile">cctype</filename></entry><entry><filename class="headerfile">climits</filename></entry><entry><filename class="headerfile">csignal</filename></entry><entry><filename class="headerfile">cstdlib</filename></entry><entry><filename class="headerfile">cwchar</filename></entry></row>
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<row><entry><filename class="headerfile">cerrno</filename></entry><entry><filename class="headerfile">clocale</filename></entry><entry><filename class="headerfile">cstdarg</filename></entry><entry><filename class="headerfile">cstring</filename></entry><entry><filename class="headerfile">cwctype</filename></entry></row>
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<row><entry><filename class="headerfile">cfloat</filename></entry><entry><filename class="headerfile">cmath</filename></entry><entry><filename class="headerfile">cstddef</filename></entry></row>
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</tbody>
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</tgroup>
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</table>
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<para>C++0x include files. These are only available in C++0x compilation mode, i.e. <code>-std=c++0x</code> or <code>-std=gnu++0x</code>.
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</para>
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<para></para>
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<table frame='all'>
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<title>C++ 200x Library Headers</title>
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<tgroup cols='5' align='left' colsep='1' rowsep='1'>
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<colspec colname='c1'></colspec>
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<colspec colname='c2'></colspec>
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<colspec colname='c3'></colspec>
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<colspec colname='c4'></colspec>
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<tbody>
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<row><entry><filename class="headerfile">algorithm</filename></entry><entry><filename class="headerfile">iomanip</filename></entry><entry><filename class="headerfile">locale</filename></entry><entry><filename class="headerfile">regex</filename></entry><entry><filename class="headerfile">tuple</filename></entry></row>
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<row><entry><filename class="headerfile">array</filename></entry><entry><filename class="headerfile">ios</filename></entry><entry><filename class="headerfile">map</filename></entry><entry><filename class="headerfile">set</filename></entry><entry><filename class="headerfile">typeinfo</filename></entry></row>
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<row><entry><filename class="headerfile">bitset</filename></entry><entry><filename class="headerfile">iosfwd</filename></entry><entry><filename class="headerfile">memory</filename></entry><entry><filename class="headerfile">sstream</filename></entry><entry><filename class="headerfile">type_traits</filename></entry></row>
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<row><entry><filename class="headerfile">complex</filename></entry><entry><filename class="headerfile">iostream</filename></entry><entry><filename class="headerfile">new</filename></entry><entry><filename class="headerfile">stack</filename></entry><entry><filename class="headerfile">unordered_map</filename></entry></row>
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<row><entry><filename class="headerfile">deque</filename></entry><entry><filename class="headerfile">istream</filename></entry><entry><filename class="headerfile">numeric</filename></entry><entry><filename class="headerfile">stdexcept</filename></entry><entry><filename class="headerfile">unordered_set</filename></entry></row>
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<row><entry><filename class="headerfile">exception</filename></entry><entry><filename class="headerfile">iterator</filename></entry><entry><filename class="headerfile">ostream</filename></entry><entry><filename class="headerfile">streambuf</filename></entry><entry><filename class="headerfile">utility</filename></entry></row>
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<row><entry><filename class="headerfile">fstream</filename></entry><entry><filename class="headerfile">limits</filename></entry><entry><filename class="headerfile">queue</filename></entry><entry><filename class="headerfile">string</filename></entry><entry><filename class="headerfile">valarray</filename></entry></row>
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<row><entry><filename class="headerfile">functional</filename></entry><entry><filename class="headerfile">list</filename></entry><entry><filename class="headerfile">random</filename></entry><entry><filename class="headerfile">system_error</filename></entry><entry><filename class="headerfile">vector</filename></entry></row>
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<row><entry><filename class="headerfile">condition_variable</filename></entry><entry><filename class="headerfile">mutex</filename></entry><entry><filename class="headerfile">thread</filename></entry><entry></entry><entry></entry></row>
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</tbody>
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</tgroup>
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</table>
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<para></para>
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<table frame='all'>
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<title>C++ 200x Library Headers for C Library Facilities</title>
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<tgroup cols='5' align='left' colsep='1' rowsep='1'>
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<colspec colname='c1'></colspec>
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<colspec colname='c2'></colspec>
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<colspec colname='c3'></colspec>
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<colspec colname='c4'></colspec>
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<colspec colname='c5'></colspec>
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<tbody>
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<row><entry><filename class="headerfile">cassert</filename></entry><entry><filename class="headerfile">cfloat</filename></entry><entry><filename class="headerfile">cmath</filename></entry><entry><filename class="headerfile">cstddef</filename></entry><entry><filename class="headerfile">ctgmath</filename></entry></row>
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<row><entry><filename class="headerfile">ccomplex</filename></entry><entry><filename class="headerfile">cinttypes</filename></entry><entry><filename class="headerfile">csetjmp</filename></entry><entry><filename class="headerfile">cstdint</filename></entry><entry><filename class="headerfile">ctime</filename></entry></row>
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<row><entry><filename class="headerfile">cctype</filename></entry><entry><filename class="headerfile">ciso646</filename></entry><entry><filename class="headerfile">csignal</filename></entry><entry><filename class="headerfile">cstdio</filename></entry><entry><filename class="headerfile">cuchar</filename></entry></row>
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<row><entry><filename class="headerfile">cerrno</filename></entry><entry><filename class="headerfile">climits</filename></entry><entry><filename class="headerfile">cstdarg</filename></entry><entry><filename class="headerfile">cstdlib</filename></entry><entry><filename class="headerfile">cwchar</filename></entry></row>
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<row><entry><filename class="headerfile">cfenv</filename></entry><entry><filename class="headerfile">clocale</filename></entry><entry><filename class="headerfile">cstdbool</filename></entry><entry><filename class="headerfile">cstring</filename></entry><entry><filename class="headerfile">cwctype</filename></entry></row>
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<row><entry><filename class="headerfile">cstdatomic</filename></entry><entry></entry><entry></entry><entry></entry><entry></entry></row>
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</tbody>
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</tgroup>
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</table>
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<para>
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In addition, TR1 includes as:
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</para>
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<table frame='all'>
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<title>C++ TR1 Library Headers</title>
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<tgroup cols='5' align='left' colsep='1' rowsep='1'>
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<colspec colname='c1'></colspec>
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<colspec colname='c2'></colspec>
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<colspec colname='c3'></colspec>
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<colspec colname='c4'></colspec>
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<colspec colname='c5'></colspec>
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<tbody>
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<row><entry><filename class="headerfile">tr1/array</filename></entry><entry><filename class="headerfile">tr1/memory</filename></entry><entry><filename class="headerfile">tr1/regex</filename></entry><entry><filename class="headerfile">tr1/type_traits</filename></entry><entry><filename class="headerfile">tr1/unordered_set</filename></entry></row>
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<row><entry><filename class="headerfile">tr1/complex</filename></entry><entry><filename class="headerfile">tr1/random</filename></entry><entry><filename class="headerfile">tr1/tuple</filename></entry><entry><filename class="headerfile">tr1/unordered_map</filename></entry><entry><filename class="headerfile">tr1/utility</filename></entry></row>
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<row><entry><filename class="headerfile">tr1/functional</filename></entry></row>
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</tbody>
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</tgroup>
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</table>
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<para></para>
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|
|
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<table frame='all'>
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<title>C++ TR1 Library Headers for C Library Facilities</title>
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<tgroup cols='5' align='left' colsep='1' rowsep='1'>
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<colspec colname='c1'></colspec>
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<colspec colname='c2'></colspec>
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<colspec colname='c3'></colspec>
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<colspec colname='c4'></colspec>
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<colspec colname='c5'></colspec>
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<tbody>
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<row><entry><filename class="headerfile">tr1/cmath</filename></entry><entry><filename class="headerfile">tr1/cfloat</filename></entry><entry><filename class="headerfile">tr1/cstdarg</filename></entry><entry><filename class="headerfile">tr1/cstdio</filename></entry><entry><filename class="headerfile">tr1/ctime</filename></entry></row>
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<row><entry><filename class="headerfile">tr1/ccomplex</filename></entry><entry><filename class="headerfile">tr1/cinttypes</filename></entry><entry><filename class="headerfile">tr1/cstdbool</filename></entry><entry><filename class="headerfile">tr1/cstdlib</filename></entry><entry><filename class="headerfile">tr1/cwchar</filename></entry></row>
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<row><entry><filename class="headerfile">tr1/cfenv</filename></entry><entry><filename class="headerfile">tr1/climits</filename></entry><entry><filename class="headerfile">tr1/cstdint</filename></entry><entry><filename class="headerfile">tr1/ctgmath</filename></entry><entry><filename class="headerfile">tr1/cwctype</filename></entry></row>
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</tbody>
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</tgroup>
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</table>
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<para>
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Also included are files for the C++ ABI interface:
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</para>
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<table frame='all'>
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<title>C++ ABI Headers</title>
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<tgroup cols='2' align='left' colsep='1' rowsep='1'>
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<colspec colname='c1'></colspec>
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<colspec colname='c2'></colspec>
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<tbody>
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<row><entry><filename class="headerfile">cxxabi.h</filename></entry><entry><filename class="headerfile">cxxabi_forced.h</filename></entry></row>
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</tbody>
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</tgroup>
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</table>
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<para>
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And a large variety of extensions.
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</para>
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<table frame='all'>
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<title>Extension Headers</title>
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<tgroup cols='5' align='left' colsep='1' rowsep='1'>
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<colspec colname='c1'></colspec>
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<colspec colname='c2'></colspec>
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<colspec colname='c3'></colspec>
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<colspec colname='c4'></colspec>
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<colspec colname='c5'></colspec>
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<tbody>
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<row><entry><filename class="headerfile">ext/algorithm</filename></entry><entry><filename class="headerfile">ext/debug_allocator.h</filename></entry><entry><filename class="headerfile">ext/mt_allocator.h</filename></entry><entry><filename class="headerfile">ext/pod_char_traits.h</filename></entry><entry><filename class="headerfile">ext/stdio_sync_filebuf.h</filename></entry></row>
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<row><entry><filename class="headerfile">ext/array_allocator.h</filename></entry><entry><filename class="headerfile">ext/enc_filebuf.h</filename></entry><entry><filename class="headerfile">ext/new_allocator.h</filename></entry><entry><filename class="headerfile">ext/pool_allocator.h</filename></entry><entry><filename class="headerfile">ext/throw_allocator.h</filename></entry></row>
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<row><entry><filename class="headerfile">ext/atomicity.h</filename></entry><entry><filename class="headerfile">ext/functional</filename></entry><entry><filename class="headerfile">ext/numeric</filename></entry><entry><filename class="headerfile">ext/rb_tree</filename></entry><entry><filename class="headerfile">ext/typelist.h</filename></entry></row>
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<row><entry><filename class="headerfile">ext/bitmap_allocator.h</filename></entry><entry><filename class="headerfile">ext/iterator</filename></entry><entry><filename class="headerfile">ext/numeric_traits.h</filename></entry><entry><filename class="headerfile">ext/rope</filename></entry><entry><filename class="headerfile">ext/type_traits.h</filename></entry></row>
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<row><entry><filename class="headerfile">ext/codecvt_specializations.h</filename></entry><entry><filename class="headerfile">ext/malloc_allocator.h</filename></entry><entry><filename class="headerfile">ext/pb_ds/assoc_container.h</filename></entry><entry><filename class="headerfile">ext/slist</filename></entry><entry><filename class="headerfile">ext/vstring.h</filename></entry></row>
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<row><entry><filename class="headerfile">ext/concurrence.h</filename></entry><entry><filename class="headerfile">ext/memory</filename></entry><entry><filename class="headerfile">ext/pb_ds/priority_queue.h</filename></entry><entry><filename class="headerfile">ext/stdio_filebuf.h</filename></entry></row>
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</tbody>
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</tgroup>
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</table>
|
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<para></para>
|
|
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<table frame='all'>
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<title>Extension Debug Headers</title>
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<tgroup cols='5' align='left' colsep='1' rowsep='1'>
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<colspec colname='c1'></colspec>
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<colspec colname='c2'></colspec>
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<colspec colname='c3'></colspec>
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<colspec colname='c4'></colspec>
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<colspec colname='c5'></colspec>
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<tbody>
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<row><entry><filename class="headerfile">debug/bitset</filename></entry><entry><filename class="headerfile">debug/list</filename></entry><entry><filename class="headerfile">debug/set</filename></entry><entry><filename class="headerfile">debug/unordered_map</filename></entry><entry><filename class="headerfile">debug/vector</filename></entry></row>
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<row><entry><filename class="headerfile">debug/deque</filename></entry><entry><filename class="headerfile">debug/map</filename></entry><entry><filename class="headerfile">debug/string</filename></entry><entry><filename class="headerfile">debug/unordered_set</filename></entry></row>
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</tbody>
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</tgroup>
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</table>
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<para></para>
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<table frame='all'>
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<title>Extension Parallel Headers</title>
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<tgroup cols='2' align='left' colsep='1' rowsep='1'>
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<colspec colname='c1'></colspec>
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<colspec colname='c2'></colspec>
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<tbody>
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<row><entry><filename class="headerfile">parallel/algorithm</filename></entry><entry><filename class="headerfile">parallel/numeric</filename></entry></row>
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</tbody>
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</tgroup>
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</table>
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</sect2>
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|
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<sect2 id="manual.intro.using.headers.mixing" xreflabel="Mixing Headers">
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<title>Mixing Headers</title>
|
|
|
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<para> A few simple rules.
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</para>
|
|
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<para>First, mixing different dialects of the standard headers is not
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possible. It's an all-or-nothing affair. Thus, code like
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</para>
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<programlisting>
|
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#include <array>
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#include <functional>
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</programlisting>
|
|
|
|
<para>Implies C++0x mode. To use the entities in <array>, the C++0x
|
|
compilation mode must be used, which implies the C++0x functionality
|
|
(and deprecations) in <functional> will be present.
|
|
</para>
|
|
|
|
<para>Second, the other headers can be included with either dialect of
|
|
the standard headers, although features and types specific to C++0x
|
|
are still only enabled when in C++0x compilation mode. So, to use
|
|
rvalue references with <code>__gnu_cxx::vstring</code>, or to use the
|
|
debug-mode versions of <code>std::unordered_map</code>, one must use
|
|
the <code>std=gnu++0x</code> compiler flag. (Or <code>std=c++0x</code>, of course.)
|
|
</para>
|
|
|
|
<para>A special case of the second rule is the mixing of TR1 and C++0x
|
|
facilities. It is possible (although not especially prudent) to
|
|
include both the TR1 version and the C++0x version of header in the
|
|
same translation unit:
|
|
</para>
|
|
|
|
<programlisting>
|
|
#include <tr1/type_traits>
|
|
#include <type_traits>
|
|
</programlisting>
|
|
|
|
<para> Several parts of C++0x diverge quite substantially from TR1 predecessors.
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 id="manual.intro.using.headers.cheaders" xreflabel="C Headers and">
|
|
<title>The C Headers and <code>namespace std</code></title>
|
|
|
|
<para>
|
|
The standard specifies that if one includes the C-style header
|
|
(<math.h> in this case), the symbols will be available
|
|
in the global namespace and perhaps in
|
|
namespace <code>std::</code> (but this is no longer a firm
|
|
requirement.) One the other hand, including the C++-style
|
|
header (<cmath>) guarantees that the entities will be
|
|
found in namespace std and perhaps in the global namespace.
|
|
</para>
|
|
|
|
<para>
|
|
Usage of C++-style headers is recommended, as then
|
|
C-linkage names can be disambiguated by explicit qualification, such
|
|
as by <code>std::abort</code>. In addition, the C++-style headers can
|
|
use function overloading to provide a simpler interface to certain
|
|
families of C-functions. For instance in <cmath>, the
|
|
function <code>std::sin</code> has overloads for all the builtin
|
|
floating-point types. This means that <code>std::sin</code> can be
|
|
used uniformly, instead of a combination
|
|
of <code>std::sinf</code>, <code>std::sin</code>,
|
|
and <code>std::sinl</code>.
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 id="manual.intro.using.headers.pre" xreflabel="Precompiled Headers">
|
|
<title>Precompiled Headers</title>
|
|
|
|
|
|
<para>There are three base header files that are provided. They can be
|
|
used to precompile the standard headers and extensions into binary
|
|
files that may the be used to speed compiles that use these headers.
|
|
</para>
|
|
|
|
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>stdc++.h</para>
|
|
<para>Includes all standard headers. Actual content varies depending on
|
|
language dialect.
|
|
</para>
|
|
</listitem>
|
|
|
|
<listitem>
|
|
<para>stdtr1c++.h</para>
|
|
<para>Includes all of <stdc++.h>, and adds all the TR1 headers.
|
|
</para>
|
|
</listitem>
|
|
|
|
<listitem><para>extc++.h</para>
|
|
<para>Includes all of <stdtr1c++.h>, and adds all the Extension headers.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
|
|
<para>How to construct a .gch file from one of these base header files.</para>
|
|
|
|
<para>First, find the include directory for the compiler. One way to do
|
|
this is:</para>
|
|
|
|
<programlisting>
|
|
g++ -v hello.cc
|
|
|
|
#include <...> search starts here:
|
|
/mnt/share/bld/H-x86-gcc.20071201/include/c++/4.3.0
|
|
...
|
|
End of search list.
|
|
</programlisting>
|
|
|
|
|
|
<para>Then, create a precompiled header file with the same flags that
|
|
will be used to compile other projects.</para>
|
|
|
|
<programlisting>
|
|
g++ -Winvalid-pch -x c++-header -g -O2 -o ./stdc++.h.gch /mnt/share/bld/H-x86-gcc.20071201/include/c++/4.3.0/x86_64-unknown-linux-gnu/bits/stdc++.h
|
|
</programlisting>
|
|
|
|
<para>The resulting file will be quite large: the current size is around
|
|
thirty megabytes. </para>
|
|
|
|
<para>How to use the resulting file.</para>
|
|
|
|
<programlisting>
|
|
g++ -I. -include stdc++.h -H -g -O2 hello.cc
|
|
</programlisting>
|
|
|
|
<para>Verification that the PCH file is being used is easy:</para>
|
|
|
|
<programlisting>
|
|
g++ -Winvalid-pch -I. -include stdc++.h -H -g -O2 hello.cc -o test.exe
|
|
! ./stdc++.h.gch
|
|
. /mnt/share/bld/H-x86-gcc.20071201/include/c++/4.3.0/iostream
|
|
. /mnt/share/bld/H-x86-gcc.20071201include/c++/4.3.0/string
|
|
</programlisting>
|
|
|
|
<para>The exclamation point to the left of the <code>stdc++.h.gch</code> listing means that the generated PCH file was used, and thus the </para>
|
|
<para></para>
|
|
|
|
<para> Detailed information about creating precompiled header files can be found in the GCC <ulink url="http://gcc.gnu.org/onlinedocs/gcc/Precompiled-Headers.html">documentation</ulink>.
|
|
</para>
|
|
|
|
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="manual.intro.using.namespaces" xreflabel="Namespaces">
|
|
<title>Namespaces</title>
|
|
|
|
<sect2 id="manual.intro.using.namespaces.all" xreflabel="Available Namespaces">
|
|
<title>Available Namespaces</title>
|
|
|
|
|
|
|
|
<para> There are three main namespaces.
|
|
</para>
|
|
|
|
<itemizedlist>
|
|
<listitem><para>std</para>
|
|
<para>The ISO C++ standards specify that "all library entities are defined
|
|
within namespace std." This includes namespaces nested
|
|
within <code>namespace std</code>, such as <code>namespace
|
|
std::tr1</code>.
|
|
</para>
|
|
</listitem>
|
|
<listitem><para>abi</para>
|
|
<para>Specified by the C++ ABI. This ABI specifies a number of type and
|
|
function APIs supplemental to those required by the ISO C++ Standard,
|
|
but necessary for interoperability.
|
|
</para>
|
|
</listitem>
|
|
|
|
<listitem><para>__gnu_</para>
|
|
<para>Indicating one of several GNU extensions. Choices
|
|
include <code>__gnu_cxx</code>, <code>__gnu_debug</code>, <code>__gnu_parallel</code>,
|
|
and <code>__gnu_pbds</code>.
|
|
</para></listitem>
|
|
</itemizedlist>
|
|
|
|
<para> A complete list of implementation namespaces (including namespace contents) is available in the generated source <ulink url="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/namespaces.html">documentation</ulink>.
|
|
</para>
|
|
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="manual.intro.using.namespaces.std" xreflabel="namespace std">
|
|
<title>namespace std</title>
|
|
|
|
|
|
<para>
|
|
One standard requirement is that the library components are defined
|
|
in <code>namespace std::</code>. Thus, in order to use these types or
|
|
functions, one must do one of two things:
|
|
</para>
|
|
|
|
<itemizedlist>
|
|
<listitem><para>put a kind of <emphasis>using-declaration</emphasis> in your source
|
|
(either <code>using namespace std;</code> or i.e. <code>using
|
|
std::string;</code>) This approach works well for individual source files, but
|
|
should not be used in a global context, like header files.
|
|
</para></listitem> <listitem><para>use a <emphasis>fully
|
|
qualified name</emphasis>for each library symbol
|
|
(i.e. <code>std::string</code>, <code>std::cout</code>) Always can be
|
|
used, and usually enhanced, by strategic use of typedefs. (In the
|
|
cases where the qualified verbiage becomes unwieldy.)
|
|
</para>
|
|
</listitem>
|
|
</itemizedlist>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="manual.intro.using.namespaces.comp" xreflabel="Using Namespace Composition">
|
|
<title>Using Namespace Composition</title>
|
|
|
|
<para>
|
|
Best practice in programming suggests sequestering new data or
|
|
functionality in a sanely-named, unique namespace whenever
|
|
possible. This is considered an advantage over dumping everything in
|
|
the global namespace, as then name look-up can be explicitly enabled or
|
|
disabled as above, symbols are consistently mangled without repetitive
|
|
naming prefixes or macros, etc.
|
|
</para>
|
|
|
|
<para>For instance, consider a project that defines most of its classes in <code>namespace gtk</code>. It is possible to
|
|
adapt <code>namespace gtk</code> to <code>namespace std</code> by using a C++-feature called
|
|
<emphasis>namespace composition</emphasis>. This is what happens if
|
|
a <emphasis>using</emphasis>-declaration is put into a
|
|
namespace-definition: the imported symbol(s) gets imported into the
|
|
currently active namespace(s). For example:
|
|
</para>
|
|
<programlisting>
|
|
namespace gtk
|
|
{
|
|
using std::string;
|
|
using std::tr1::array;
|
|
|
|
class Window { ... };
|
|
}
|
|
</programlisting>
|
|
<para>
|
|
In this example, <code>std::string</code> gets imported into
|
|
<code>namespace gtk</code>. The result is that use of
|
|
<code>std::string</code> inside namespace gtk can just use <code>string</code>, without the explicit qualification.
|
|
As an added bonus,
|
|
<code>std::string</code> does not get imported into
|
|
the global namespace. Additionally, a more elaborate arrangement can be made for backwards compatibility and portability, whereby the
|
|
<code>using</code>-declarations can wrapped in macros that
|
|
are set based on autoconf-tests to either "" or i.e. <code>using
|
|
std::string;</code> (depending on whether the system has
|
|
libstdc++ in <code>std::</code> or not). (ideas from
|
|
<email>llewelly@dbritsch.dsl.xmission.com</email>, Karl Nelson <email>kenelson@ece.ucdavis.edu</email>)
|
|
</para>
|
|
|
|
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="manual.intro.using.macros" xreflabel="Macros">
|
|
<title>Macros</title>
|
|
|
|
<para>All pre-processor switches and configurations are all gathered
|
|
in the file <code>c++config.h</code>, which is generated during
|
|
the libstdc++ configuration and build process, and included by
|
|
files part of the public libstdc++ API. Most of these macros
|
|
should not be used by consumers of libstdc++, and are reserved
|
|
for internal implementation use. <emphasis>These macros cannot be
|
|
redefined</emphasis>. However, a select handful of these macro
|
|
control libstdc++ extensions and extra features, or provide
|
|
versioning information for the API, and are able to be used.
|
|
</para>
|
|
|
|
<para>All library macros begin with <code>_GLIBCXX_</code> (except for
|
|
versions 3.1.x to 3.3.x, which use <code>_GLIBCPP_</code>).
|
|
</para>
|
|
|
|
<para>Below is the macro which users may check for library version
|
|
information. </para>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><code>__GLIBCXX__</code></term>
|
|
<listitem>
|
|
<para>The current version of
|
|
libstdc++ in compressed ISO date format, form of an unsigned
|
|
long. For details on the value of this particular macro for a
|
|
particular release, please consult this <ulink url="abi.html">
|
|
document</ulink>.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
<para>Below are the macros which users may change with #define/#undef or
|
|
with -D/-U compiler flags. The default state of the symbol is
|
|
listed.</para>
|
|
|
|
<para><quote>Configurable</quote> (or <quote>Not configurable</quote>) means
|
|
that the symbol is initially chosen (or not) based on
|
|
--enable/--disable options at library build and configure time
|
|
(documented <link linkend="manual.intro.setup.configure">here</link>), with the
|
|
various --enable/--disable choices being translated to
|
|
#define/#undef).
|
|
</para>
|
|
|
|
<para> <acronym>ABI</acronym> means that changing from the default value may
|
|
mean changing the <acronym>ABI</acronym> of compiled code. In other words, these
|
|
choices control code which has already been compiled (i.e., in a
|
|
binary such as libstdc++.a/.so). If you explicitly #define or
|
|
#undef these macros, the <emphasis>headers</emphasis> may see different code
|
|
paths, but the <emphasis>libraries</emphasis> which you link against will not.
|
|
Experimenting with different values with the expectation of
|
|
consistent linkage requires changing the config headers before
|
|
building/installing the library.
|
|
</para>
|
|
|
|
<variablelist>
|
|
<varlistentry><term><code>_GLIBCXX_DEPRECATED</code></term>
|
|
<listitem>
|
|
<para>
|
|
Defined by default. Not configurable. ABI-changing. Turning this off
|
|
removes older ARM-style iostreams code, and other anachronisms
|
|
from the API. This macro is dependent on the version of the
|
|
standard being tracked, and as a result may give different results for
|
|
<code>-std=c++98</code> and <code>-std=c++0x</code>. This may
|
|
be useful in updating old C++ code which no longer meet the
|
|
requirements of the language, or for checking current code
|
|
against new language standards.
|
|
</para>
|
|
</listitem></varlistentry>
|
|
|
|
<varlistentry><term><code>_GLIBCXX_FORCE_NEW</code></term>
|
|
<listitem>
|
|
<para>
|
|
Undefined by default. When defined, memory allocation and
|
|
allocators controlled by libstdc++ call operator new/delete
|
|
without caching and pooling. Configurable via
|
|
<code>--enable-libstdcxx-allocator</code>. ABI-changing.
|
|
</para>
|
|
</listitem></varlistentry>
|
|
|
|
|
|
<varlistentry><term><code>_GLIBCXX_CONCEPT_CHECKS</code></term>
|
|
<listitem>
|
|
<para>
|
|
Undefined by default. Configurable via
|
|
<code>--enable-concept-checks</code>. When defined, performs
|
|
compile-time checking on certain template instantiations to
|
|
detect violations of the requirements of the standard. This
|
|
is described in more detail <ulink
|
|
url="../19_diagnostics/howto.html#3">here</ulink>.
|
|
</para>
|
|
</listitem></varlistentry>
|
|
|
|
<varlistentry><term><code>_GLIBCXX_DEBUG</code></term>
|
|
<listitem>
|
|
<para>
|
|
Undefined by default. When defined, compiles
|
|
user code using the <ulink url="../ext/debug.html#safe">libstdc++ debug
|
|
mode</ulink>.
|
|
</para>
|
|
</listitem></varlistentry>
|
|
<varlistentry><term><code>_GLIBCXX_DEBUG_PEDANTIC</code></term>
|
|
<listitem>
|
|
<para>
|
|
Undefined by default. When defined while
|
|
compiling with the <ulink url="../ext/debug.html#safe">libstdc++ debug
|
|
mode</ulink>, makes the debug mode extremely picky by making the use
|
|
of libstdc++ extensions and libstdc++-specific behavior into
|
|
errors.
|
|
</para>
|
|
</listitem></varlistentry>
|
|
<varlistentry><term><code>_GLIBCXX_PARALLEL</code></term>
|
|
<listitem>
|
|
<para>Undefined by default. When defined, compiles
|
|
user code using the <ulink url="../ext/parallel_mode.html">libstdc++ parallel
|
|
mode</ulink>.
|
|
</para>
|
|
</listitem></varlistentry>
|
|
</variablelist>
|
|
|
|
|
|
</sect1>
|
|
|
|
<sect1 id="manual.intro.using.concurrency" xreflabel="Concurrency">
|
|
<title>Concurrency</title>
|
|
|
|
<para>This section discusses issues surrounding the proper compilation
|
|
of multithreaded applications which use the Standard C++
|
|
library. This information is GCC-specific since the C++
|
|
standard does not address matters of multithreaded applications.
|
|
</para>
|
|
|
|
<sect2 id="manual.intro.using.concurrency.prereq" xreflabel="Thread Prereq">
|
|
<title>Prerequisites</title>
|
|
|
|
<para>All normal disclaimers aside, multithreaded C++ application are
|
|
only supported when libstdc++ and all user code was built with
|
|
compilers which report (via <code> gcc/g++ -v </code>) the same thread
|
|
model and that model is not <emphasis>single</emphasis>. As long as your
|
|
final application is actually single-threaded, then it should be
|
|
safe to mix user code built with a thread model of
|
|
<emphasis>single</emphasis> with a libstdc++ and other C++ libraries built
|
|
with another thread model useful on the platform. Other mixes
|
|
may or may not work but are not considered supported. (Thus, if
|
|
you distribute a shared C++ library in binary form only, it may
|
|
be best to compile it with a GCC configured with
|
|
--enable-threads for maximal interchangeability and usefulness
|
|
with a user population that may have built GCC with either
|
|
--enable-threads or --disable-threads.)
|
|
</para>
|
|
<para>When you link a multithreaded application, you will probably
|
|
need to add a library or flag to g++. This is a very
|
|
non-standardized area of GCC across ports. Some ports support a
|
|
special flag (the spelling isn't even standardized yet) to add
|
|
all required macros to a compilation (if any such flags are
|
|
required then you must provide the flag for all compilations not
|
|
just linking) and link-library additions and/or replacements at
|
|
link time. The documentation is weak. Here is a quick summary
|
|
to display how ad hoc this is: On Solaris, both -pthreads and
|
|
-threads (with subtly different meanings) are honored. On OSF,
|
|
-pthread and -threads (with subtly different meanings) are
|
|
honored. On Linux/i386, -pthread is honored. On FreeBSD,
|
|
-pthread is honored. Some other ports use other switches.
|
|
AFAIK, none of this is properly documented anywhere other than
|
|
in ``gcc -dumpspecs'' (look at lib and cpp entries).
|
|
</para>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="manual.intro.using.concurrency.thread_safety" xreflabel="Thread Safety">
|
|
<title>Thread Safety</title>
|
|
|
|
|
|
<para>
|
|
We currently use the <ulink url="http://www.sgi.com/tech/stl/thread_safety.html">SGI STL</ulink> definition of thread safety.
|
|
</para>
|
|
|
|
|
|
<para>The library strives to be thread-safe when all of the following
|
|
conditions are met:
|
|
</para>
|
|
<itemizedlist>
|
|
<listitem>
|
|
<para>The system's libc is itself thread-safe,
|
|
</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
The compiler in use reports a thread model other than
|
|
'single'. This can be tested via output from <code>gcc
|
|
-v</code>. Multi-thread capable versions of gcc output
|
|
something like this:
|
|
</para>
|
|
<programlisting>
|
|
%gcc -v
|
|
Using built-in specs.
|
|
...
|
|
Thread model: posix
|
|
gcc version 4.1.2 20070925 (Red Hat 4.1.2-33)
|
|
</programlisting>
|
|
|
|
<para>Look for "Thread model" lines that aren't equal to "single."</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
Requisite command-line flags are used for atomic operations
|
|
and threading. Examples of this include <code>-pthread</code>
|
|
and <code>-march=native</code>, although specifics vary
|
|
depending on the host environment. See <ulink
|
|
url="http://gcc.gnu.org/onlinedocs/gcc/Option-Summary.html">Machine
|
|
Dependent Options</ulink>.
|
|
</para>
|
|
</listitem>
|
|
<listitem>
|
|
<para>
|
|
An implementation of atomicity.h functions
|
|
exists for the architecture in question. See the internals documentation for more <ulink url="../ext/concurrence.html">details</ulink>.
|
|
</para>
|
|
</listitem>
|
|
|
|
</itemizedlist>
|
|
<para>The user-code must guard against concurrent method calls which may
|
|
access any particular library object's state. Typically, the
|
|
application programmer may infer what object locks must be held
|
|
based on the objects referenced in a method call. Without getting
|
|
into great detail, here is an example which requires user-level
|
|
locks:
|
|
</para>
|
|
<programlisting>
|
|
library_class_a shared_object_a;
|
|
|
|
thread_main () {
|
|
library_class_b *object_b = new library_class_b;
|
|
shared_object_a.add_b (object_b); // must hold lock for shared_object_a
|
|
shared_object_a.mutate (); // must hold lock for shared_object_a
|
|
}
|
|
|
|
// Multiple copies of thread_main() are started in independent threads.</programlisting>
|
|
<para>Under the assumption that object_a and object_b are never exposed to
|
|
another thread, here is an example that should not require any
|
|
user-level locks:
|
|
</para>
|
|
<programlisting>
|
|
thread_main () {
|
|
library_class_a object_a;
|
|
library_class_b *object_b = new library_class_b;
|
|
object_a.add_b (object_b);
|
|
object_a.mutate ();
|
|
} </programlisting>
|
|
<para>All library objects are safe to use in a multithreaded program as
|
|
long as each thread carefully locks out access by any other
|
|
thread while it uses any object visible to another thread, i.e.,
|
|
treat library objects like any other shared resource. In general,
|
|
this requirement includes both read and write access to objects;
|
|
unless otherwise documented as safe, do not assume that two threads
|
|
may access a shared standard library object at the same time.
|
|
</para>
|
|
<para>See chapters <ulink url="../17_intro/howto.html#3">17</ulink> (library
|
|
introduction), <ulink url="../23_containers/howto.html#3">23</ulink>
|
|
(containers), and <ulink url="../27_io/howto.html#9">27</ulink> (I/O) for
|
|
more information.
|
|
</para>
|
|
|
|
|
|
</sect2>
|
|
<sect2 id="manual.intro.using.concurrency.atomics" xreflabel="Atomics">
|
|
<title>Atomics</title>
|
|
<para>
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 id="manual.intro.using.concurrency.io" xreflabel="IO">
|
|
<title>IO</title>
|
|
<para>I'll assume that you have already read the
|
|
<ulink url="../17_intro/howto.html#3">general notes on library threads</ulink>,
|
|
and the
|
|
<ulink url="../23_containers/howto.html#3">notes on threaded container
|
|
access</ulink> (you might not think of an I/O stream as a container, but
|
|
the points made there also hold here). If you have not read them,
|
|
please do so first.
|
|
</para>
|
|
<para>This gets a bit tricky. Please read carefully, and bear with me.
|
|
</para>
|
|
|
|
<sect3 id="concurrency.io.structure" xreflabel="Structure">
|
|
<title>Structure</title>
|
|
<para>A wrapper
|
|
type called <code>__basic_file</code> provides our abstraction layer
|
|
for the <code>std::filebuf</code> classes. Nearly all decisions dealing
|
|
with actual input and output must be made in <code>__basic_file</code>.
|
|
</para>
|
|
<para>A generic locking mechanism is somewhat in place at the filebuf layer,
|
|
but is not used in the current code. Providing locking at any higher
|
|
level is akin to providing locking within containers, and is not done
|
|
for the same reasons (see the links above).
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="concurrency.io.defaults" xreflabel="Defaults">
|
|
<title>Defaults</title>
|
|
<para>The __basic_file type is simply a collection of small wrappers around
|
|
the C stdio layer (again, see the link under Structure). We do no
|
|
locking ourselves, but simply pass through to calls to <code>fopen</code>,
|
|
<code>fwrite</code>, and so forth.
|
|
</para>
|
|
<para>So, for 3.0, the question of "is multithreading safe for I/O"
|
|
must be answered with, "is your platform's C library threadsafe
|
|
for I/O?" Some are by default, some are not; many offer multiple
|
|
implementations of the C library with varying tradeoffs of threadsafety
|
|
and efficiency. You, the programmer, are always required to take care
|
|
with multiple threads.
|
|
</para>
|
|
<para>(As an example, the POSIX standard requires that C stdio FILE*
|
|
operations are atomic. POSIX-conforming C libraries (e.g, on Solaris
|
|
and GNU/Linux) have an internal mutex to serialize operations on
|
|
FILE*s. However, you still need to not do stupid things like calling
|
|
<code>fclose(fs)</code> in one thread followed by an access of
|
|
<code>fs</code> in another.)
|
|
</para>
|
|
<para>So, if your platform's C library is threadsafe, then your
|
|
<code>fstream</code> I/O operations will be threadsafe at the lowest
|
|
level. For higher-level operations, such as manipulating the data
|
|
contained in the stream formatting classes (e.g., setting up callbacks
|
|
inside an <code>std::ofstream</code>), you need to guard such accesses
|
|
like any other critical shared resource.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="concurrency.io.future" xreflabel="Future">
|
|
<title>Future</title>
|
|
<para> A
|
|
second choice may be available for I/O implementations: libio. This is
|
|
disabled by default, and in fact will not currently work due to other
|
|
issues. It will be revisited, however.
|
|
</para>
|
|
<para>The libio code is a subset of the guts of the GNU libc (glibc) I/O
|
|
implementation. When libio is in use, the <code>__basic_file</code>
|
|
type is basically derived from FILE. (The real situation is more
|
|
complex than that... it's derived from an internal type used to
|
|
implement FILE. See libio/libioP.h to see scary things done with
|
|
vtbls.) The result is that there is no "layer" of C stdio
|
|
to go through; the filebuf makes calls directly into the same
|
|
functions used to implement <code>fread</code>, <code>fwrite</code>,
|
|
and so forth, using internal data structures. (And when I say
|
|
"makes calls directly," I mean the function is literally
|
|
replaced by a jump into an internal function. Fast but frightening.
|
|
*grin*)
|
|
</para>
|
|
<para>Also, the libio internal locks are used. This requires pulling in
|
|
large chunks of glibc, such as a pthreads implementation, and is one
|
|
of the issues preventing widespread use of libio as the libstdc++
|
|
cstdio implementation.
|
|
</para>
|
|
<para>But we plan to make this work, at least as an option if not a future
|
|
default. Platforms running a copy of glibc with a recent-enough
|
|
version will see calls from libstdc++ directly into the glibc already
|
|
installed. For other platforms, a copy of the libio subsection will
|
|
be built and included in libstdc++.
|
|
</para>
|
|
</sect3>
|
|
|
|
<sect3 id="concurrency.io.alt" xreflabel="Alt">
|
|
<title>Alternatives</title>
|
|
<para>Don't forget that other cstdio implementations are possible. You could
|
|
easily write one to perform your own forms of locking, to solve your
|
|
"interesting" problems.
|
|
</para>
|
|
</sect3>
|
|
|
|
</sect2>
|
|
|
|
<sect2 id="manual.intro.using.concurrency.containers" xreflabel="Containers">
|
|
<title>Containers</title>
|
|
|
|
<para>This section discusses issues surrounding the design of
|
|
multithreaded applications which use Standard C++ containers.
|
|
All information in this section is current as of the gcc 3.0
|
|
release and all later point releases. Although earlier gcc
|
|
releases had a different approach to threading configuration and
|
|
proper compilation, the basic code design rules presented here
|
|
were similar. For information on all other aspects of
|
|
multithreading as it relates to libstdc++, including details on
|
|
the proper compilation of threaded code (and compatibility between
|
|
threaded and non-threaded code), see Chapter 17.
|
|
</para>
|
|
<para>Two excellent pages to read when working with the Standard C++
|
|
containers and threads are
|
|
<ulink url="http://www.sgi.com/tech/stl/thread_safety.html">SGI's
|
|
http://www.sgi.com/tech/stl/thread_safety.html</ulink> and
|
|
<ulink url="http://www.sgi.com/tech/stl/Allocators.html">SGI's
|
|
http://www.sgi.com/tech/stl/Allocators.html</ulink>.
|
|
</para>
|
|
<para><emphasis>However, please ignore all discussions about the user-level
|
|
configuration of the lock implementation inside the STL
|
|
container-memory allocator on those pages. For the sake of this
|
|
discussion, libstdc++ configures the SGI STL implementation,
|
|
not you. This is quite different from how gcc pre-3.0 worked.
|
|
In particular, past advice was for people using g++ to
|
|
explicitly define _PTHREADS or other macros or port-specific
|
|
compilation options on the command line to get a thread-safe
|
|
STL. This is no longer required for any port and should no
|
|
longer be done unless you really know what you are doing and
|
|
assume all responsibility.</emphasis>
|
|
</para>
|
|
<para>Since the container implementation of libstdc++ uses the SGI
|
|
code, we use the same definition of thread safety as SGI when
|
|
discussing design. A key point that beginners may miss is the
|
|
fourth major paragraph of the first page mentioned above
|
|
("For most clients,"...), which points out that
|
|
locking must nearly always be done outside the container, by
|
|
client code (that'd be you, not us). There is a notable
|
|
exceptions to this rule. Allocators called while a container or
|
|
element is constructed uses an internal lock obtained and
|
|
released solely within libstdc++ code (in fact, this is the
|
|
reason STL requires any knowledge of the thread configuration).
|
|
</para>
|
|
<para>For implementing a container which does its own locking, it is
|
|
trivial to provide a wrapper class which obtains the lock (as
|
|
SGI suggests), performs the container operation, and then
|
|
releases the lock. This could be templatized <emphasis>to a certain
|
|
extent</emphasis>, on the underlying container and/or a locking
|
|
mechanism. Trying to provide a catch-all general template
|
|
solution would probably be more trouble than it's worth.
|
|
</para>
|
|
<para>The STL implementation is currently configured to use the
|
|
high-speed caching memory allocator. Some people like to
|
|
test and/or normally run threaded programs with a different
|
|
default. For all details about how to globally override this
|
|
at application run-time see <ulink url="../ext/howto.html#3">here</ulink>.
|
|
</para>
|
|
<para>There is a better way (not standardized yet): It is possible to
|
|
force the malloc-based allocator on a per-case-basis for some
|
|
application code. The library team generally believes that this
|
|
is a better way to tune an application for high-speed using this
|
|
implementation of the STL. There is
|
|
<ulink url="../ext/howto.html#3">more information on allocators here</ulink>.
|
|
</para>
|
|
|
|
</sect2>
|
|
</sect1>
|
|
|
|
<sect1 id="manual.intro.using.exception" xreflabel="Exceptions">
|
|
<title>Exceptions</title>
|
|
|
|
<sect2 id="intro.using.exception.propagating" xreflabel="Propagating Exceptions">
|
|
|
|
<title>Propagating Exceptions aka Exception Neutrality</title>
|
|
<para>
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 id="intro.using.exception.safety" xreflabel="Exception Safety">
|
|
<title>Exception Safety</title>
|
|
<para>
|
|
</para>
|
|
</sect2>
|
|
|
|
<sect2 id="intro.using.exception.no" xreflabel="-fno-exceptions">
|
|
<title>Support for <literal>-fno-exceptions</literal></title>
|
|
<para>
|
|
</para>
|
|
</sect2>
|
|
|
|
</sect1>
|
|
|
|
<!-- Section 0x : Debug -->
|
|
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
|
|
parse="xml" href="debug.xml">
|
|
</xi:include>
|
|
|
|
</chapter>
|