diff options
| author | bkoz <bkoz@138bc75d-0d04-0410-961f-82ee72b054a4> | 2008-01-18 08:16:51 +0000 |
|---|---|---|
| committer | bkoz <bkoz@138bc75d-0d04-0410-961f-82ee72b054a4> | 2008-01-18 08:16:51 +0000 |
| commit | 0aeadebf36eab6d537b67b38c5dcacf648f2f69f (patch) | |
| tree | 0fd3dc60ac26e2ec9502783b72d38867bcb418d8 /libstdc++-v3/docs/html/20_util/howto.html | |
| parent | 9e61be0719e3f9d3bda483eaaf71ee67f02e81ae (diff) | |
| download | ppe42-gcc-0aeadebf36eab6d537b67b38c5dcacf648f2f69f.tar.gz ppe42-gcc-0aeadebf36eab6d537b67b38c5dcacf648f2f69f.zip | |
2008-01-18 Benjamin Kosnik <bkoz@redhat.com>
* docs/*: To...
* doc/*: ...here.
* testsuite/Makefile.am: Move doc-performance to...
* Makefile.am: Add doc to SUBDIRS, move doxygen-* rules to...
* doc/Makefile.am: Consolidate documentation creation here.
(doc-doxygen-html): New.
(doc-doxygen-man): New.
(doc-performance): New.
* doc/Makefile.in: New.
* acinclude.m4 (glibcxx_SUBDIRS): Add doc directory.
* doc/doxygen/guide.html: Edit for unified html configuration.
* doc/doxygen/mainpage.html: Same.
* doc/doxygen/run_doxygen: Same, more namespace fixups for man
generation.
* doc/doxygen/user.cfg.in: Update for doxygen 1.5.4.
* include/tr1_impl/random: Remove maint from doxygen markup.
* include/tr1_impl/functional: Same.
* include/std/tuple: Same.
* include/std/streambuf: Same.
* include/std/bitset: Same.
* include/std/limits: Same.
* include/std/fstream: Same.
* include/std/istream: Same.
* include/std/sstream: Same.
* include/ext/pool_allocator.h: Same.
* include/ext/rc_string_base.h: Same.
* include/bits/basic_ios.h: Same.
* include/bits/stl_list.h: Same.
* include/bits/stl_map.h: Same.
* include/bits/locale_classes.h: Same.
* include/bits/stl_set.h: Same.
* include/bits/stl_iterator_base_types.h: Same.
* include/bits/basic_string.h: Same.
* include/bits/stl_multimap.h: Same.
* include/bits/stl_vector.h: Same.
* include/bits/ios_base.h: Same.
* include/bits/stl_deque.h: Same.
* include/bits/postypes.h: Same.
* include/bits/stl_multiset.h: Same.
* include/bits/stl_algo.h: Same.
* include/bits/stl_iterator.h: Same.
* include/bits/stl_tempbuf.h: Same.
* include/bits/stl_construct.h: Same.
* include/bits/stl_relops.h: Same.
* include/tr1/tuple: Same.
* include/backward/auto_ptr.h: Same.
* testsuite/23_containers/vector/requirements/dr438/assign_neg.cc:
Fixups for line number changes.
* testsuite/23_containers/vector/requirements/dr438/insert_neg.cc: Same.
* testsuite/23_containers/vector/requirements/dr438/
constructor_1_neg.cc: Same.
* testsuite/23_containers/vector/requirements/dr438/
constructor_2_neg.cc: Same.
* testsuite/23_containers/deque/requirements/dr438/assign_neg.cc: Same.
* testsuite/23_containers/deque/requirements/dr438/insert_neg.cc: Same.
* testsuite/23_containers/deque/requirements/dr438/
constructor_1_neg.cc: Same.
* testsuite/23_containers/deque/requirements/dr438/
constructor_2_neg.cc: Same.
* testsuite/23_containers/list/requirements/dr438/assign_neg.cc: Same.
* testsuite/23_containers/list/requirements/dr438/insert_neg.cc: Same.
* testsuite/23_containers/list/requirements/dr438/
constructor_1_neg.cc: Same.
* testsuite/23_containers/list/requirements/dr438/
constructor_2_neg.cc: Same.
* testsuite/20_util/auto_ptr/assign_neg.cc: Same.
* aclocal.m4: Regenerate.
* config.h.in: Regenerate.
* configure: Regenerate.
* Makefile.in: Regenerate.
* src/Makefile.in: Regenerate.
* po/Makefile.in: Regenerate.
* libmath/Makefile.in: Regenerate.
* include/Makefile.in: Regenerate.
* libsupc++/Makefile.in: Regenerate.
* testsuite/Makefile.in: Regenerate.
* scripts/make_graphs.py: Correct paths for new layout.
2008-01-17 Benjamin Kosnik <bkoz@redhat.com>
* acinclude.m4 (AC_LC_MESSAGES): Remove serial.
* linkage.m4 (AC_REPLACE_MATHFUNCS): Same.
* configure: Regenerate.
* aclocal.m4: Regenerate.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@131625 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'libstdc++-v3/docs/html/20_util/howto.html')
| -rw-r--r-- | libstdc++-v3/docs/html/20_util/howto.html | 234 |
1 files changed, 0 insertions, 234 deletions
diff --git a/libstdc++-v3/docs/html/20_util/howto.html b/libstdc++-v3/docs/html/20_util/howto.html deleted file mode 100644 index fb02aa169fb..00000000000 --- a/libstdc++-v3/docs/html/20_util/howto.html +++ /dev/null @@ -1,234 +0,0 @@ -<?xml version="1.0" encoding="ISO-8859-1"?> -<!DOCTYPE html - PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" - "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> - -<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> -<head> - <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> - <meta name="AUTHOR" content="pme@gcc.gnu.org (Phil Edwards)" /> - <meta name="KEYWORDS" content="HOWTO, libstdc++, GCC, g++, libg++, STL" /> - <meta name="DESCRIPTION" content="HOWTO for the libstdc++ chapter 20." /> - <meta name="GENERATOR" content="vi and eight fingers" /> - <title>libstdc++ HOWTO: Chapter 20: General Utilities</title> -<link rel="StyleSheet" href="../lib3styles.css" type="text/css" /> -<link rel="Start" href="../documentation.html" type="text/html" - title="GNU C++ Standard Library" /> -<link rel="Prev" href="../19_diagnostics/howto.html" type="text/html" - title="Diagnostics" /> -<link rel="Next" href="../21_strings/howto.html" type="text/html" - title="Strings" /> -<link rel="Bookmark" href="allocator.html" type="text/html" - title="Allocators and allocation" /> -<link rel="Copyright" href="../17_intro/license.html" type="text/html" /> -<link rel="Help" href="../faq/index.html" type="text/html" title="F.A.Q." /> -</head> -<body> - -<h1 class="centered"><a name="top">Chapter 20: General Utilities</a></h1> - -<p>Chapter 20 deals with utility classes and functions, such as - the oft-debated <code>auto_ptr<></code>. -</p> - - -<!-- ####################################################### --> -<hr /> -<h1>Contents</h1> -<ul> - <li><a href="#1"><code>auto_ptr</code> is not omnipotent</a></li> - <li><a href="#2"><code>auto_ptr</code> inside container classes</a></li> - <li><a href="#3">Functors</a></li> - <li><a href="#4">Pairs</a></li> - <li><a href="#5">Memory allocators</a></li> -</ul> - -<hr /> - -<!-- ####################################################### --> - -<h2><a name="1"><code>auto_ptr</code> is not omnipotent</a></h2> - <p>I'm not going to try and explain all of the fun and delicious - things that can happen with misuse of the auto_ptr class template - (called AP here), nor am I going to try and teach you how to use - AP safely in the presence of copying. The AP class is a really - nifty idea for a smart pointer, but it is one of the dumbest of - all the smart pointers -- and that's fine. - </p> - <p>AP is not meant to be a supersmart solution to all resource - leaks everywhere. Neither is it meant to be an effective form - of garbage collection (although it can help, a little bit). - And it can <em>not</em> be used for arrays! - </p> - <p>AP <em>is</em> meant to prevent nasty leaks in the presence of - exceptions. That's <em>all</em>. This code is AP-friendly: - </p> - <pre> - // not a recommend naming scheme, but good for web-based FAQs - typedef std::auto_ptr<MyClass> APMC; - - extern function_taking_MyClass_pointer (MyClass*); - extern some_throwable_function (); - - void func (int data) - { - APMC ap (new MyClass(data)); - - some_throwable_function(); // this will throw an exception - - function_taking_MyClass_pointer (ap.get()); - } - </pre> - <p>When an exception gets thrown, the instance of MyClass that's - been created on the heap will be <code>delete</code>'d as the stack is - unwound past <code>func()</code>. - </p> - <p>Changing that code as follows is <em>not</em> AP-friendly: - </p> - <pre> - APMC ap (new MyClass[22]); - </pre> - <p>You will get the same problems as you would without the use - of AP: - </p> - <pre> - char* array = new char[10]; // array new... - ... - delete array; // ...but single-object delete - </pre> - <p>AP cannot tell whether the pointer you've passed at creation points - to one or many things. If it points to many things, you are about - to die. AP is trivial to write, however, so you could write your - own <code>auto_array_ptr</code> for that situation (in fact, this has - been done many times; check the mailing lists, Usenet, Boost, etc). - </p> - <p>Return <a href="#top">to top of page</a> or - <a href="../faq/index.html">to the FAQ</a>. - </p> - -<hr /> -<h2><a name="2"><code>auto_ptr</code> inside container classes</a></h2> - <p>All of the <a href="../23_containers/howto.html">containers</a> - described in the standard library require their contained types - to have, among other things, a copy constructor like this: - </p> - <pre> - struct My_Type - { - My_Type (My_Type const&); - }; - </pre> - <p>Note the const keyword; the object being copied shouldn't change. - The template class <code>auto_ptr</code> (called AP here) does not - meet this requirement. Creating a new AP by copying an existing - one transfers ownership of the pointed-to object, which means that - the AP being copied must change, which in turn means that the - copy ctors of AP do not take const objects. - </p> - <p>The resulting rule is simple: <em>Never ever use a container of - auto_ptr objects.</em> The standard says that "undefined" - behavior is the result, but it is guaranteed to be messy. - </p> - <p>To prevent you from doing this to yourself, the - <a href="../19_diagnostics/howto.html#3">concept checks</a> built - in to this implementation will issue an error if you try to - compile code like this: - </p> - <pre> - #include <vector> - #include <memory> - - void f() - { - std::vector< std::auto_ptr<int> > vec_ap_int; - } - </pre> - <p>Should you try this with the checks enabled, you will see an error. - </p> - <p>Return <a href="#top">to top of page</a> or - <a href="../faq/index.html">to the FAQ</a>. - </p> - -<hr /> -<h2><a name="3">Functors</a></h2> - <p>If you don't know what functors are, you're not alone. Many people - get slightly the wrong idea. In the interest of not reinventing - the wheel, we will refer you to the introduction to the functor - concept written by SGI as part of their STL, in - <a href="http://www.sgi.com/tech/stl/functors.html">their - http://www.sgi.com/tech/stl/functors.html</a>. - </p> - <p>Return <a href="#top">to top of page</a> or - <a href="../faq/index.html">to the FAQ</a>. - </p> - -<hr /> -<h2><a name="4">Pairs</a></h2> - <p>The <code>pair<T1,T2></code> is a simple and handy way to - carry around a pair of objects. One is of type T1, and another of - type T2; they may be the same type, but you don't get anything - extra if they are. The two members can be accessed directly, as - <code>.first</code> and <code>.second</code>. - </p> - <p>Construction is simple. The default ctor initializes each member - with its respective default ctor. The other simple ctor, - </p> - <pre> - pair (const T1& x, const T2& y); - </pre> - <p>does what you think it does, <code>first</code> getting <code>x</code> - and <code>second</code> getting <code>y</code>. - </p> - <p>There is a copy constructor, but it requires that your compiler - handle member function templates: - </p> - <pre> - template <class U, class V> pair (const pair<U,V>& p); - </pre> - <p>The compiler will convert as necessary from U to T1 and from - V to T2 in order to perform the respective initializations. - </p> - <p>The comparison operators are done for you. Equality - of two <code>pair<T1,T2></code>s is defined as both <code>first</code> - members comparing equal and both <code>second</code> members comparing - equal; this simply delegates responsibility to the respective - <code>operator==</code> functions (for types like MyClass) or builtin - comparisons (for types like int, char, etc). - </p> - <p><a name="pairlt"> - The less-than operator is a bit odd the first time you see it. It - is defined as evaluating to: - </a> - </p> - <pre> - x.first < y.first || - ( !(y.first < x.first) && x.second < y.second ) - </pre> - <p>The other operators are not defined using the <code>rel_ops</code> - functions above, but their semantics are the same. - </p> - <p>Finally, there is a template function called <code>make_pair</code> - that takes two references-to-const objects and returns an - instance of a pair instantiated on their respective types: - </p> - <pre> - pair<int,MyClass> p = make_pair(4,myobject); - </pre> - - <p>Return <a href="#top">to top of page</a> or - <a href="../faq/index.html">to the FAQ</a>. - </p> - - -<!-- ####################################################### --> - -<hr /> -<p class="fineprint"><em> -See <a href="../17_intro/license.html">license.html</a> for copying conditions. -Comments and suggestions are welcome, and may be sent to -<a href="mailto:libstdc++@gcc.gnu.org">the libstdc++ mailing list</a>. -</em></p> - - -</body> -</html> |
