The autoconf examples at
http://gcc.gnu.org/onlinedocs/libstdc++/manual/backwards.html#id541888
are incorrect, relying on pre-standard semantics for rvalue
references, and missing out several C++11 headers. This patch
corrects those examples.
This also tweaks some markup in the file, and adds some xml:id
attributes to ensure stable anchors when the HTML is regenerated, so
the link above will become
http://gcc.gnu.org/onlinedocs/libstdc++/manual/backwards.html#backwards.third.support_cxx11
and stay the same in future.
* doc/xml/manual/backwards_compatibility.xml: Fix autoconf tests for
C++11 compiler features and library headers. Add stable id
attributes. Use <filename> element for headers and surround in angle
brackets. Use <classname> for classes.
* doc/html/*: Regenerate.
Committed to trunk.
Index: doc/xml/manual/backwards_compatibility.xml
===================================================================
--- doc/xml/manual/backwards_compatibility.xml (revision 181041)
+++ doc/xml/manual/backwards_compatibility.xml (working copy)
@@ -42,24 +42,24 @@ Committee couldn't include everything, a
<para>Portability notes and known implementation limitations are as follows.</para>
-<section><info><title>No <code>ios_base</code></title></info>
+<section xml:id="backwards.first.ios_base"><info><title>No <code>ios_base</code></title></info>
<para> At least some older implementations don't have <code>std::ios_base</code>, so you should use <code>std::ios::badbit</code>, <code>std::ios::failbit</code> and <code>std::ios::eofbit</code> and <code>std::ios::goodbit</code>.
</para>
</section>
-<section><info><title>No <code>cout</code> in <code>ostream.h</code>, no <code>cin</code> in <code>istream.h</code></title></info>
+<section xml:id="backwards.first.cout_cin"><info><title>No <code>cout</code> in <filename class="headerfile"><ostream.h></filename>, no <code>cin</code> in <filename class="headerfile"><istream.h></filename></title></info>
<para>
In earlier versions of the standard,
- <filename class="headerfile">fstream.h</filename>,
- <filename class="headerfile">ostream.h</filename>
- and <filename class="headerfile">istream.h</filename>
+ <filename class="headerfile"><fstream.h></filename>,
+ <filename class="headerfile"><ostream.h></filename>
+ and <filename class="headerfile"><istream.h></filename>
used to define
<code>cout</code>, <code>cin</code> and so on. ISO C++ specifies that one needs to include
- <filename class="headerfile">iostream</filename>
+ <filename class="headerfile"><iostream></filename>
explicitly to get the required definitions.
</para>
<para> Some include adjustment may be required.</para>
@@ -96,7 +96,7 @@ considered replaced and rewritten.
Portability notes and known implementation limitations are as follows.
</para>
-<section><info><title>Namespace <code>std::</code> not supported</title></info>
+<section xml:id="backwards.second.std"><info><title>Namespace <code>std::</code> not supported</title></info>
<para>
@@ -114,7 +114,7 @@ considered replaced and rewritten.
First, see if the compiler has a flag for this. Namespace
back-portability-issues are generally not a problem for g++
compilers that do not have libstdc++ in <code>std::</code>, as the
- compilers use <code>-fno-honor-std</code> (ignore
+ compilers use <option>-fno-honor-std</option> (ignore
<code>std::</code>, <code>:: = std::</code>) by default. That is,
the responsibility for enabling or disabling <code>std::</code> is
on the user; the maintainer does not have to care about it. This
@@ -182,7 +182,7 @@ AC_DEFUN([AC_CXX_NAMESPACE_STD], [
</programlisting>
</section>
-<section><info><title>Illegal iterator usage</title></info>
+<section xml:id="backwards.second.iterators"><info><title>Illegal iterator usage</title></info>
<para>
The following illustrate implementation-allowed illegal iterator
@@ -212,12 +212,12 @@ AC_DEFUN([AC_CXX_NAMESPACE_STD], [
</itemizedlist>
</section>
-<section><info><title><code>isspace</code> from <filename class="headerfile">cctype</filename> is a macro
+<section xml:id="backwards.second.isspace"><info><title><code>isspace</code> from <filename class="headerfile"><cctype></filename> is a macro
</title></info>
<para>
- Glibc 2.0.x and 2.1.x define <filename class="headerfile">ctype.h</filename> functionality as macros
+ Glibc 2.0.x and 2.1.x define <filename class="headerfile"><ctype.h></filename> functionality as macros
(isspace, isalpha etc.).
</para>
@@ -242,7 +242,7 @@ std:: (__ctype_b[(int) ( ( 'X' ) )] &
<para>
A solution is to modify a header-file so that the compiler tells
- <filename class="headerfile">ctype.h</filename> to define functions
+ <filename class="headerfile"><ctype.h></filename> to define functions
instead of macros:
</para>
@@ -254,20 +254,21 @@ std:: (__ctype_b[(int) ( ( 'X' ) )] &
</programlisting>
<para>
- Then, include <filename class="headerfile">ctype.h</filename>
+ Then, include <filename class="headerfile"><ctype.h></filename>
</para>
<para>
Another problem arises if you put a <code>using namespace
- std;</code> declaration at the top, and include <filename class="headerfile">ctype.h</filename>. This will result in
- ambiguities between the definitions in the global namespace
- (<filename class="headerfile">ctype.h</filename>) and the
+ std;</code> declaration at the top, and include
+ <filename class="headerfile"><ctype.h></filename>. This will
+ result in ambiguities between the definitions in the global namespace
+ (<filename class="headerfile"><ctype.h></filename>) and the
definitions in namespace <code>std::</code>
(<code><cctype></code>).
</para>
</section>
-<section><info><title>No <code>vector::at</code>, <code>deque::at</code>, <code>string::at</code></title></info>
+<section xml:id="backwards.second.at"><info><title>No <code>vector::at</code>, <code>deque::at</code>, <code>string::at</code></title></info>
<para>
@@ -304,7 +305,7 @@ AC_DEFINE(HAVE_CONTAINER_AT)],
</section>
-<section><info><title>No <code>std::char_traits<char>::eof</code></title></info>
+<section xml:id="backwards.second.eof"><info><title>No <code>std::char_traits<char>::eof</code></title></info>
<para>
@@ -321,7 +322,7 @@ AC_DEFINE(HAVE_CONTAINER_AT)],
</section>
-<section><info><title>No <code>string::clear</code></title></info>
+<section xml:id="backwards.second.stringclear"><info><title>No <code>string::clear</code></title></info>
<para>
@@ -351,7 +352,7 @@ erase(size_type __pos = 0, size_type __n
</para>
</section>
-<section><info><title>
+<section xml:id="backwards.second.ostreamform_istreamscan"><info><title>
Removal of <code>ostream::form</code> and <code>istream::scan</code>
extensions
</title></info>
@@ -362,14 +363,14 @@ erase(size_type __pos = 0, size_type __n
</para>
</section>
-<section><info><title>No <code>basic_stringbuf</code>, <code>basic_stringstream</code></title></info>
+<section xml:id="backwards.second.stringstreams"><info><title>No <code>basic_stringbuf</code>, <code>basic_stringstream</code></title></info>
<para>
Although the ISO standard <code>i/ostringstream</code>-classes are
- provided, (<filename class="headerfile">sstream</filename>), for
+ provided, (<filename class="headerfile"><sstream></filename>), for
compatibility with older implementations the pre-ISO
- <code>i/ostrstream</code> (<filename class="headerfile">strstream</filename>) interface is also provided,
+ <code>i/ostrstream</code> (<filename class="headerfile"><strstream></filename>) interface is also provided,
with these caveats:
</para>
@@ -490,7 +491,7 @@ particular <quote>info iostream</quote>.
</para>
</section>
-<section><info><title>Little or no wide character support</title></info>
+<section xml:id="backwards.second.wchar"><info><title>Little or no wide character support</title></info>
<para>
Classes <classname>wstring</classname> and
@@ -499,7 +500,7 @@ particular <quote>info iostream</quote>.
</para>
</section>
-<section><info><title>No templatized iostreams</title></info>
+<section xml:id="backwards.second.iostream_templates"><info><title>No templatized iostreams</title></info>
<para>
Classes <classname>wfilebuf</classname> and
@@ -507,7 +508,7 @@ particular <quote>info iostream</quote>.
</para>
</section>
-<section><info><title>Thread safety issues</title></info>
+<section xml:id="backwards.second.thread_safety"><info><title>Thread safety issues</title></info>
<para>
@@ -601,11 +602,12 @@ libstdc++-v3.
<para>Portability notes and known implementation limitations are as follows.</para>
-<section><info><title>Pre-ISO headers moved to backwards or removed</title></info>
+<section xml:id="backwards.third.headers"><info><title>Pre-ISO headers moved to backwards or removed</title></info>
<para> The pre-ISO C++ headers
- (<code>iostream.h</code>, <code>defalloc.h</code> etc.) are
+ (<filename class="headerfile"><iostream.h></filename>,
+ <filename class="headerfile"><defalloc.h></filename> etc.) are
available, unlike previous libstdc++ versions, but inclusion
generates a warning that you are using deprecated headers.
</para>
@@ -681,29 +683,30 @@ AC_DEFUN([AC_HEADER_PRE_STDCXX], [
</programlisting>
<para>Porting between pre-ISO headers and ISO headers is simple: headers
-like <filename class="headerfile">vector.h</filename> can be replaced with <filename class="headerfile">vector</filename> and a using
+like <filename class="headerfile"><vector.h></filename> can be replaced with <filename class="headerfile"><vector></filename> and a using
directive <code>using namespace std;</code> can be put at the global
scope. This should be enough to get this code compiling, assuming the
other usage is correct.
</para>
</section>
-<section><info><title>Extension headers hash_map, hash_set moved to ext or backwards</title></info>
+<section xml:id="backwards.third.hash"><info><title>Extension headers hash_map, hash_set moved to ext or backwards</title></info>
<para>At this time most of the features of the SGI STL extension have been
replaced by standardized libraries.
- In particular, the <code>unordered_map</code> and
- <code>unordered_set</code> containers of TR1 and C++ 2011 are suitable
- replacements for the non-standard <code>hash_map</code> and
- <code>hash_set</code> containers in the SGI STL.
+ In particular, the <classname>unordered_map</classname> and
+ <classname>unordered_set</classname> containers of TR1 and C++ 2011
+ are suitable replacements for the non-standard
+ <classname>hash_map</classname> and <classname>hash_set</classname>
+ containers in the SGI STL.
</para>
-<para> Header files <filename class="headerfile">hash_map</filename> and <filename class="headerfile">hash_set</filename> moved
-to <filename class="headerfile">ext/hash_map</filename> and <filename class="headerfile">ext/hash_set</filename>,
+<para> Header files <filename class="headerfile"><hash_map></filename> and <filename class="headerfile"><hash_set></filename> moved
+to <filename class="headerfile"><ext/hash_map></filename> and <filename class="headerfile"><ext/hash_set></filename>,
respectively. At the same time, all types in these files are enclosed
in <code>namespace __gnu_cxx</code>. Later versions deprecate
-these files, and suggest using TR1's <filename class="headerfile">unordered_map</filename>
-and <filename class="headerfile">unordered_set</filename> instead.
+these files, and suggest using TR1's <filename class="headerfile"><unordered_map></filename>
+and <filename class="headerfile"><unordered_set></filename> instead.
</para>
<para>The extensions are no longer in the global or <code>std</code>
@@ -779,7 +782,7 @@ AC_DEFUN([AC_HEADER_EXT_HASH_SET], [
</programlisting>
</section>
-<section><info><title>No <code>ios::nocreate/ios::noreplace</code>.
+<section xml:id="backwards.third.nocreate_noreplace"><info><title>No <code>ios::nocreate/ios::noreplace</code>.
</title></info>
@@ -798,7 +801,7 @@ and <code>trunc</code> (except for <code
</para>
</section>
-<section><info><title>
+<section xml:id="backwards.third.streamattach"><info><title>
No <code>stream::attach(int fd)</code>
</title></info>
@@ -820,7 +823,7 @@ No <code>stream::attach(int fd)</code>
<para>
An extension is available that implements this.
- <filename class="headerfile">ext/stdio_filebuf.h</filename> contains a derived class called
+ <filename class="headerfile"><ext/stdio_filebuf.h></filename> contains a derived class called
<link xmlns:xlink="http://www.w3.org/1999/xlink"; xlink:href="http://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen/a00074.html";><code>__gnu_cxx::stdio_filebuf</code></link>.
This class can be constructed from a C <code>FILE*</code> or a file
descriptor, and provides the <code>fd()</code> function.
@@ -833,7 +836,7 @@ No <code>stream::attach(int fd)</code>
</para>
</section>
-<section xml:id="backwards.support_cxx98"><info><title>
+<section xml:id="backwards.third.support_cxx98"><info><title>
Support for C++98 dialect.
</title></info>
@@ -909,7 +912,7 @@ AC_DEFUN([AC_HEADER_STDCXX_98], [
</programlisting>
</section>
-<section xml:id="backwards.support_tr1"><info><title>
+<section xml:id="backwards.third.support_tr1"><info><title>
Support for C++TR1 dialect.
</title></info>
@@ -1001,7 +1004,7 @@ AC_DEFUN([AC_HEADER_TR1_UNORDERED_SET],
</section>
-<section xml:id="backwards.support_cxx11"><info><title>
+<section xml:id="backwards.third.support_cxx11"><info><title>
Support for C++11 dialect.
</title></info>
@@ -1018,9 +1021,9 @@ AC_DEFUN([AC_COMPILE_STDCXX_11], [
AC_LANG_CPLUSPLUS
AC_TRY_COMPILE([
template <typename T>
- struct check
+ struct check final
{
- static_assert(sizeof(int) <= sizeof(T), "not big enough");
+ static constexpr T value{ __cplusplus };
};
typedef check<check<bool>> right_angle_brackets;
@@ -1029,8 +1032,10 @@ AC_DEFUN([AC_COMPILE_STDCXX_11], [
decltype(a) b;
typedef check<int> check_type;
- check_type c;
- check_type&& cr = c;],,
+ check_type c{};
+ check_type&& cr = static_cast<check_type&&>(c);
+
+ static_assert(check_type::value == 201103L, "C++11 compiler");],,
ac_cv_cxx_compile_cxx11_native=yes, ac_cv_cxx_compile_cxx11_native=no)
AC_LANG_RESTORE
])
@@ -1043,9 +1048,9 @@ AC_DEFUN([AC_COMPILE_STDCXX_11], [
CXXFLAGS="$CXXFLAGS -std=c++11"
AC_TRY_COMPILE([
template <typename T>
- struct check
+ struct check final
{
- static_assert(sizeof(int) <= sizeof(T), "not big enough");
+ static constexpr T value{ __cplusplus };
};
typedef check<check<bool>> right_angle_brackets;
@@ -1054,8 +1059,10 @@ AC_DEFUN([AC_COMPILE_STDCXX_11], [
decltype(a) b;
typedef check<int> check_type;
- check_type c;
- check_type&& cr = c;],,
+ check_type c{};
+ check_type&& cr = static_cast<check_type&&>(c);
+
+ static_assert(check_type::value == 201103L, "C++11 compiler");],,
ac_cv_cxx_compile_cxx11_cxx=yes, ac_cv_cxx_compile_cxx11_cxx=no)
CXXFLAGS="$ac_save_CXXFLAGS"
AC_LANG_RESTORE
@@ -1069,9 +1076,9 @@ AC_DEFUN([AC_COMPILE_STDCXX_11], [
CXXFLAGS="$CXXFLAGS -std=gnu++11"
AC_TRY_COMPILE([
template <typename T>
- struct check
+ struct check final
{
- static_assert(sizeof(int) <= sizeof(T), "not big enough");
+ static constexpr T value{ __cplusplus };
};
typedef check<check<bool>> right_angle_brackets;
@@ -1080,8 +1087,10 @@ AC_DEFUN([AC_COMPILE_STDCXX_11], [
decltype(a) b;
typedef check<int> check_type;
- check_type c;
- check_type&& cr = c;],,
+ check_type c{};
+ check_type&& cr = static_cast<check_type&&>(c);
+
+ static_assert(check_type::value == 201103L, "C++11 compiler");],,
ac_cv_cxx_compile_cxx11_gxx=yes, ac_cv_cxx_compile_cxx11_gxx=no)
CXXFLAGS="$ac_save_CXXFLAGS"
AC_LANG_RESTORE
@@ -1097,6 +1106,8 @@ AC_DEFUN([AC_COMPILE_STDCXX_11], [
<para>Check for library coverage of the C++2011 standard.
+ (Some library headers are commented out in this check, they are
+ not currently provided by libstdc++).
</para>
<programlisting>
@@ -1124,6 +1135,7 @@ AC_DEFUN([AC_HEADER_STDCXX_11], [
#include <cmath>
#include <csetjmp>
#include <csignal>
+ // #include <cstdalign>
#include <cstdarg>
#include <cstdbool>
#include <cstddef>
@@ -1133,21 +1145,29 @@ AC_DEFUN([AC_HEADER_STDCXX_11], [
#include <cstring>
#include <ctgmath>
#include <ctime>
+ // #include <cuchar>
#include <cwchar>
#include <cwctype>
#include <algorithm>
#include <array>
+ #include <atomic>
#include <bitset>
+ #include <chrono>
+ // #include <codecvt>
#include <complex>
+ #include <condition_variable>
#include <deque>
#include <exception>
+ #include <forward_list>
#include <fstream>
#include <functional>
+ #include <future>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
+ #include <initializer_list>
#include <istream>
#include <iterator>
#include <limits>
@@ -1155,19 +1175,25 @@ AC_DEFUN([AC_HEADER_STDCXX_11], [
#include <locale>
#include <map>
#include <memory>
+ #include <mutex>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <random>
+ #include <ratio>
#include <regex>
+ #include <scoped_allocator>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
+ #include <system_error>
+ #include <thread>
#include <tuple>
+ #include <typeindex>
#include <typeinfo>
#include <type_traits>
#include <unordered_map>
@@ -1186,7 +1212,8 @@ AC_DEFUN([AC_HEADER_STDCXX_11], [
])
</programlisting>
-<para>As is the case for TR1 support, these autoconf macros can be made for a finer-grained, per-header-file check. For <unordered_map>
+<para>As is the case for TR1 support, these autoconf macros can be made for a finer-grained, per-header-file check. For
+<filename class="headerfile"><unordered_map></filename>
</para>
<programlisting>
@@ -1243,8 +1270,8 @@ AC_DEFUN([AC_HEADER_UNORDERED_SET], [
</section>
-<section><info><title>
- Container::iterator_type is not necessarily Container::value_type*
+<section xml:id="backwards.third.iterator_type"><info><title>
+ <code>Container::iterator_type</code> is not necessarily <code>Container::value_type*</code>
</title></info>
