From 0aeadebf36eab6d537b67b38c5dcacf648f2f69f Mon Sep 17 00:00:00 2001 From: bkoz Date: Fri, 18 Jan 2008 08:16:51 +0000 Subject: 2008-01-18 Benjamin Kosnik * 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 * 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 --- .../doc/html/17_intro/backwards_compatibility.html | 1073 ++++++++++++++++++++ 1 file changed, 1073 insertions(+) create mode 100644 libstdc++-v3/doc/html/17_intro/backwards_compatibility.html (limited to 'libstdc++-v3/doc/html/17_intro/backwards_compatibility.html') diff --git a/libstdc++-v3/doc/html/17_intro/backwards_compatibility.html b/libstdc++-v3/doc/html/17_intro/backwards_compatibility.html new file mode 100644 index 00000000000..c9af980f0fc --- /dev/null +++ b/libstdc++-v3/doc/html/17_intro/backwards_compatibility.html @@ -0,0 +1,1073 @@ + + + + + + + + + + Backwards Compatibility + + + + + + +

Backwards Compatibility

+ +

+ The latest version of this document is always available at + + http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/backwards_compatibility.html. +

+ +

+ To the libstdc++ homepage. +

+ + +
+

+ First. +

+ +

The first generation GNU C++ library was called libg++. It was a +separate GNU project, although reliably paired with GCC. Rumors imply +that it had a working relationship with at least two kinds of +dinosaur. +

+ +

Known Issues include many of the limitations of its immediate ancestor.

+ +

Portability notes and known implementation limitations are as follows.

+ +
No ios_base
+ +

At least some older implementations don't have std::ios_base, so you should use std::ios::badbit, std::ios::failbit and std::ios::eofbit and std::ios::goodbit. +

+ +
No cout in ostream.h, no cin in istream.h
+ +

+ In earlier versions of the standard, + <fstream.h>, + <ostream.h> + and <istream.h> + used to define + cout, cin and so on. ISO C++ specifies that one needs to include + <iostream> + explicitly to get the required definitions. +

+

Some include adjustment may be required.

+ + +

This project is no longer maintained or supported, and the sources +archived. The code is considered replaced and rewritten. +

+ +
+

+ Second. +

+

The second generation GNU C++ library was called libstdc++, or +libstdc++-v2. It spans the time between libg++ and pre-ISO C++ +standardization and is usually associated with the following GCC +releases: egcs 1.x, gcc 2.95, and gcc 2.96. +

+ +

The STL portions of this library are based on SGI/HP STL release 3.11. +

+ +

Portability notes and known implementation limitations are as follows.

+ +
Namespace std:: not supported
+ +

+ Some care is required to support C++ compiler and or library + implementation that do not have the standard library in + namespace std. +

+

+ The following sections list some possible solutions to support compilers + that cannot ignore std::-qualified names. +

+ +

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 std::, as + the compilers use -fno-honor-std (ignore + std::, :: = std::) by default. That + is, the responsibility for enabling or disabling + std:: is on the user; the maintainer does not have + to care about it. This probably applies to some other compilers + as well. +

+ +

Second, experiment with a variety of pre-processor tricks.

+ +

By defining std as a macro, fully-qualified namespace calls become global. Volia.

+ +
+#ifdef WICKEDLY_OLD_COMPILER
+# define std
+#endif
+
+(thanks to Juergen Heinzl who posted this solution on gnu.gcc.help) + +

Another pre-processor based approach is to define a +macro NAMESPACE_STD, which is defined to either +"" or "std" based on a compile-type test. On GNU +systems, this can be done with autotools by means of an autoconf test +(see below) for HAVE_NAMESPACE_STD, then using that to +set a value for the NAMESPACE_STD macro. At that point, +one is able to use NAMESPACE_STD::string, which will +evaluate to std::string or +::string (ie, in the global namespace on systems that do +not put string in std::).

+ +
+dnl @synopsis AC_CXX_NAMESPACE_STD
+dnl
+dnl If the compiler supports namespace std, define
+dnl HAVE_NAMESPACE_STD.
+dnl
+dnl @category Cxx
+dnl @author Todd Veldhuizen
+dnl @author Luc Maisonobe <luc@spaceroots.org>
+dnl @version 2004-02-04
+dnl @license AllPermissive
+AC_DEFUN([AC_CXX_NAMESPACE_STD], [
+  AC_CACHE_CHECK(if g++ supports namespace std,
+  ac_cv_cxx_have_std_namespace,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  AC_TRY_COMPILE([#include <iostream> 
+                  std::istream& is = std::cin;],,
+  ac_cv_cxx_have_std_namespace=yes, ac_cv_cxx_have_std_namespace=no)
+  AC_LANG_RESTORE
+  ])
+  if test "$ac_cv_cxx_have_std_namespace" = yes; then
+    AC_DEFINE(HAVE_NAMESPACE_STD,,[Define if g++ supports namespace std. ])
+  fi
+])
+
+ +
Illegal iterator usage
+

+ The following illustrate implementation-allowed illegal iterator + use, and then correct use. +

+ +

  • you cannot do + ostream::operator<<(iterator) to print the + address of the iterator => use operator<< + &*iterator instead +

    • +

  • you cannot clear an iterator's reference + (iterator = 0) => use + iterator = iterator_type(); +

    • +

  • +if (iterator) won't work any + more => use if (iterator != iterator_type()) +

    • +
+ +
isspace from <cctype> is a macro +
+ +

Glibc 2.0.x and 2.1.x define <ctype.h> +functionality as macros (isspace, isalpha etc.). +

+ +

+This implementations of libstdc++, however, keep these functions as +macros, and so it is not back-portable to use fully qualified +names. For example: +

+ +
 
+#include <cctype> 
+int main() { std::isspace('X'); } 
+
+ +

Results in something like this: +

+ +
 
+std:: (__ctype_b[(int) ( ( 'X' ) )] & (unsigned short int) _ISspace ) ; 
+
+ + +

A solution is to modify a header-file so that the compiler tells +<ctype.h> to define functions instead of macros: +

+ +
+// This keeps isalnum, et al from being propagated as macros. 
+#if __linux__
+# define __NO_CTYPE 1
+#endif
+
+ +

Then, include <ctype.h> +

+ +

+Another problem arises if you put a using namespace std; +declaration at the top, and include <ctype.h>. This +will result in ambiguities between the definitions in the global +namespace (<ctype.h>) and the definitions in namespace +std:: (<cctype>). +

+ +
No vector::at, deque::at, string::at
+ +

+ One solution is to add an autoconf-test for this: +

+
+AC_MSG_CHECKING(for container::at)
+AC_TRY_COMPILE(
+[
+#include <vector>
+#include <deque>
+#include <string>
+	
+using namespace std;
+],
+[
+deque<int> test_deque(3);
+test_deque.at(2);
+vector<int> test_vector(2);
+test_vector.at(1);
+string test_string("test_string");
+test_string.at(3);
+],
+[AC_MSG_RESULT(yes)
+AC_DEFINE(HAVE_CONTAINER_AT)],
+[AC_MSG_RESULT(no)])
+
+ +

+If you are using other (non-GNU) compilers it might be a good idea +to check for string::at separately. +

+ +
No std::char_traits<char>::eof
+ +

+Use some kind of autoconf test, plus this: +

+
 
+#ifdef HAVE_CHAR_TRAITS
+#define CPP_EOF std::char_traits<char>::eof()
+#else
+#define CPP_EOF EOF
+#endif
+
+ +
No string::clear
+ +

+ There are two functions for deleting the contents of a string: + clear and erase (the latter + returns the string). +

+ +
+void 
+clear() { _M_mutate(0, this->size(), 0); }
+
+
+basic_string& 
+erase(size_type __pos = 0, size_type __n = npos)
+{ 
+  return this->replace(_M_check(__pos), _M_fold(__pos, __n),
+                          _M_data(), _M_data()); 
+}
+
+ +

+ Unfortunately, ut clear is not + implemented in this version, so you should use + erase (which is probably faster than + operator=(charT*)). +

+ +
Removal of ostream::form and +istream::scan extensions
+ +

These are no longer supported. Please use + + stringstreams instead. +

+ +
No basic_stringbuf, basic_stringstream
+ +

+Although the ISO standard +i/ostringstream-classes are provided, (<sstream>), for compatibility with older implementations the pre-ISO i/ostrstream (<strstream>) interface is also provided, with these caveats: +

+ +
    +

  • strstream is considered to be + deprecated +

    • +

  • strstream is limited to + char +

    • +

  • with ostringstream you don't + have to take care of terminating the string or freeing its + memory +

    • +

  • istringstream can be re-filled + (clear(); str(input);) +

    • +
+

+ You can then use output-stringstreams like this: +

+ +
+#ifdef HAVE_SSTREAM
+# include <sstream>
+#else
+# include <strstream>
+#endif
+
+#ifdef HAVE_SSTREAM
+  std::ostringstream oss;
+#else
+  std::ostrstream oss;
+#endif
+
+oss << "Name=" << m_name << ", number=" << m_number << std::endl;
+...
+#ifndef HAVE_SSTREAM
+  oss << std::ends; // terminate the char*-string
+#endif
+
+// str() returns char* for ostrstream and a string for ostringstream
+// this also causes ostrstream to think that the buffer's memory
+// is yours
+m_label.set_text(oss.str());
+#ifndef HAVE_SSTREAM
+  // let the ostrstream take care of freeing the memory
+  oss.freeze(false);
+#endif
+
+ +

+ Input-stringstreams can be used similarly: +

+ +
 
+std::string input;
+...
+#ifdef HAVE_SSTREAM
+std::istringstream iss(input);
+#else
+std::istrstream iss(input.c_str());
+#endif
+
+int i;
+iss >> i; 
+
+ +

One (the only?) restriction is that an istrstream cannot be re-filled: +

+ +
+std::istringstream iss(numerator);
+iss >> m_num;
+// this is not possible with istrstream
+iss.clear();
+iss.str(denominator);
+iss >> m_den;
+
+ +

+If you don't care about speed, you can put these conversions in + a template-function: +

+
+template <class X>
+void fromString(const string& input, X& any)
+{
+#ifdef HAVE_SSTREAM
+std::istringstream iss(input);
+#else
+std::istrstream iss(input.c_str());
+#endif
+X temp;
+iss >> temp;
+if (iss.fail())
+throw runtime_error(..)
+any = temp;
+}
+
+ +

Another example of using stringstreams is in this howto. +

+ +

There is additional information in the libstdc++-v2 info files, in +particular "info iostream". +

+ +
Little or no wide character support
+ +
No templatized iostreams
+ +
Thread safety issues
+ +

This project is no longer maintained or supported, and the sources +archived. The code is considered replaced and rewritten. +

+ + +
+

+ Third. +

+

The third generation GNU C++ library is called libstdc++, or +libstdc++-v3. +

+ +

The subset commonly known as the Standard Template Library + (chapters 23 through 25, mostly) is adapted from the final release + of the SGI STL (version 3.3), with extensive changes. +

+ +

A more formal description of the V3 goals can be found in the + official design document. +

+ +

Portability notes and known implementation limitations are as follows.

+ +
Pre-ISO headers moved to backwards or removed
+ +

The pre-ISO C++ headers + (iostream.h, defalloc.h etc.) are + available, unlike previous libstdc++ versions, but inclusion + generates a warning that you are using deprecated headers. +

+ +

This compatibility layer is constructed by including the + standard C++ headers, and injecting any items in + std:: into the global namespace. +

+

For those of you new to ISO C++ (welcome, time travelers!), no, + that isn't a typo. Yes, the headers really have new names. + Marshall Cline's C++ FAQ Lite has a good explanation in item + [27.4]. +

+ +

Some include adjustment may be required. What follows is an +autoconf test that defines PRE_STDCXX_HEADERS when they +exist.

+ +
+# AC_HEADER_PRE_STDCXX
+AC_DEFUN([AC_HEADER_PRE_STDCXX], [
+  AC_CACHE_CHECK(for pre-ISO C++ include files,
+  ac_cv_cxx_pre_stdcxx,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -Wno-deprecated"	
+
+  # Omit defalloc.h, as compilation with newer compilers is problematic.
+  AC_TRY_COMPILE([
+  #include <new.h>
+  #include <iterator.h>
+  #include <alloc.h>
+  #include <set.h>
+  #include <hashtable.h>
+  #include <hash_set.h>
+  #include <fstream.h>
+  #include <tempbuf.h>
+  #include <istream.h>
+  #include <bvector.h>
+  #include <stack.h>
+  #include <rope.h>
+  #include <complex.h>
+  #include <ostream.h>
+  #include <heap.h>
+  #include <iostream.h>
+  #include <function.h>
+  #include <multimap.h>
+  #include <pair.h>
+  #include <stream.h>
+  #include <iomanip.h>
+  #include <slist.h>
+  #include <tree.h>
+  #include <vector.h>
+  #include <deque.h>
+  #include <multiset.h>
+  #include <list.h>
+  #include <map.h>
+  #include <algobase.h>
+  #include <hash_map.h>
+  #include <algo.h>
+  #include <queue.h>
+  #include <streambuf.h>
+  ],,
+  ac_cv_cxx_pre_stdcxx=yes, ac_cv_cxx_pre_stdcxx=no)
+  CXXFLAGS="$ac_save_CXXFLAGS"
+  AC_LANG_RESTORE
+  ])
+  if test "$ac_cv_cxx_pre_stdcxx" = yes; then
+    AC_DEFINE(PRE_STDCXX_HEADERS,,[Define if pre-ISO C++ header files are present. ])
+  fi
+])
+
+ +

Porting between pre-ISO headers and ISO headers is simple: headers +like <vector.h> can be replaced with <vector> and a using +directive using namespace std; can be put at the global +scope. This should be enough to get this code compiling, assuming the +other usage is correct. +

+ +
Extension headers hash_map, hash_set moved to ext or backwards
+ +

Header files hash_map and hash_set moved +to ext/hash_map and ext/hash_set, +respectively. At the same time, all types in these files are enclosed +in namespace __gnu_cxx. Later versions move deprecate +these files, and suggest using TR1's unordered_map +and unordered_set instead. +

+ +

The following autoconf tests check for working HP/SGI hash containers. +

+ +
+# AC_HEADER_EXT_HASH_MAP
+AC_DEFUN([AC_HEADER_EXT_HASH_MAP], [
+  AC_CACHE_CHECK(for ext/hash_map,
+  ac_cv_cxx_ext_hash_map,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -Werror"	
+  AC_TRY_COMPILE([#include <ext/hash_map>], [using __gnu_cxx::hash_map;],
+  ac_cv_cxx_ext_hash_map=yes, ac_cv_cxx_ext_hash_map=no)
+  CXXFLAGS="$ac_save_CXXFLAGS"
+  AC_LANG_RESTORE
+  ])
+  if test "$ac_cv_cxx_ext_hash_map" = yes; then
+    AC_DEFINE(HAVE_EXT_HASH_MAP,,[Define if ext/hash_map is present. ])
+  fi
+])
+
+ +
+# AC_HEADER_EXT_HASH_SET
+AC_DEFUN([AC_HEADER_EXT_HASH_SET], [
+  AC_CACHE_CHECK(for ext/hash_set,
+  ac_cv_cxx_ext_hash_set,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -Werror"	
+  AC_TRY_COMPILE([#include <ext/hash_set>], [using __gnu_cxx::hash_set;],
+  ac_cv_cxx_ext_hash_set=yes, ac_cv_cxx_ext_hash_set=no)
+  CXXFLAGS="$ac_save_CXXFLAGS"
+  AC_LANG_RESTORE
+  ])
+  if test "$ac_cv_cxx_ext_hash_set" = yes; then
+    AC_DEFINE(HAVE_EXT_HASH_SET,,[Define if ext/hash_set is present. ])
+  fi
+])
+
+ + +
+No ios::nocreate/ios::noreplace. +
+ +

The existence of ios::nocreate being used for +input-streams has been confirmed, most probably because the author +thought it would be more correct to specify nocreate explicitly. So +it can be left out for input-streams. +

+ +

For output streams, "nocreate" is probably the default, +unless you specify std::ios::trunc ? To be safe, you can +open the file for reading, check if it has been opened, and then +decide whether you want to create/replace or not. To my knowledge, +even older implementations support app, ate +and trunc (except for app ?). +

+ + +
+No stream::attach(int fd) +
+ +

+ Phil Edwards writes: It was considered and rejected for the ISO + standard. Not all environments use file descriptors. Of those + that do, not all of them use integers to represent them. +

+ +

+ For a portable solution (among systems which use + filedescriptors), you need to implement a subclass of + std::streambuf (or + std::basic_streambuf<..>) which opens a file + given a descriptor, and then pass an instance of this to the + stream-constructor. +

+ +

+ An extension is available that implements this. + <ext/stdio_filebuf.h> contains a derived class called + __gnu_cxx::stdio_filebuf. + This class can be constructed from a C FILE* or a file + descriptor, and provides the fd() function. +

+ +

+ For another example of this, refer to + fdstream example + by Nicolai Josuttis. +

+ +
+Support for C++98 dialect. +
+ +

Check for complete library coverage of the C++1998/2003 standard. +

+ +
+
+# AC_HEADER_STDCXX_98
+AC_DEFUN([AC_HEADER_STDCXX_98], [
+  AC_CACHE_CHECK(for ISO C++ 98 include files,
+  ac_cv_cxx_stdcxx_98,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  AC_TRY_COMPILE([
+    #include <cassert>
+    #include <cctype>
+    #include <cerrno>
+    #include <cfloat>
+    #include <ciso646>
+    #include <climits>
+    #include <clocale>
+    #include <cmath>
+    #include <csetjmp>
+    #include <csignal>
+    #include <cstdarg>
+    #include <cstddef>
+    #include <cstdio>
+    #include <cstdlib>
+    #include <cstring>
+    #include <ctime>
+
+    #include <algorithm>
+    #include <bitset>
+    #include <complex>
+    #include <deque>
+    #include <exception>
+    #include <fstream>
+    #include <functional>
+    #include <iomanip>
+    #include <ios>
+    #include <iosfwd>
+    #include <iostream>
+    #include <istream>
+    #include <iterator>
+    #include <limits>
+    #include <list>
+    #include <locale>
+    #include <map>
+    #include <memory>
+    #include <new>
+    #include <numeric>
+    #include <ostream>
+    #include <queue>
+    #include <set>
+    #include <sstream>
+    #include <stack>
+    #include <stdexcept>
+    #include <streambuf>
+    #include <string>
+    #include <typeinfo>
+    #include <utility>
+    #include <valarray>
+    #include <vector>
+  ],,
+  ac_cv_cxx_stdcxx_98=yes, ac_cv_cxx_stdcxx_98=no)
+  AC_LANG_RESTORE
+  ])
+  if test "$ac_cv_cxx_stdcxx_98" = yes; then
+    AC_DEFINE(STDCXX_98_HEADERS,,[Define if ISO C++ 1998 header files are present. ])
+  fi
+])
+
+ + +
+Support for C++TR1 dialect. +
+ +

Check for library coverage of the TR1 standard. +

+ +
+
+# AC_HEADER_STDCXX_TR1
+AC_DEFUN([AC_HEADER_STDCXX_TR1], [
+  AC_CACHE_CHECK(for ISO C++ TR1 include files,
+  ac_cv_cxx_stdcxx_tr1,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  AC_TRY_COMPILE([
+  #include <tr1/array>
+  #include <tr1/ccomplex>
+  #include <tr1/cctype>
+  #include <tr1/cfenv>
+  #include <tr1/cfloat>
+  #include <tr1/cinttypes>
+  #include <tr1/climits>
+  #include <tr1/cmath>
+  #include <tr1/complex>
+  #include <tr1/cstdarg>
+  #include <tr1/cstdbool>
+  #include <tr1/cstdint>
+  #include <tr1/cstdio>
+  #include <tr1/cstdlib>
+  #include <tr1/ctgmath>
+  #include <tr1/ctime>
+  #include <tr1/cwchar>
+  #include <tr1/cwctype>
+  #include <tr1/functional>
+  #include <tr1/memory>
+  #include <tr1/random>
+  #include <tr1/regex>
+  #include <tr1/tuple>
+  #include <tr1/type_traits>
+  #include <tr1/unordered_set>
+  #include <tr1/unordered_map>
+  #include <tr1/utility>
+  ],,
+  ac_cv_cxx_stdcxx_tr1=yes, ac_cv_cxx_stdcxx_tr1=no)
+  AC_LANG_RESTORE
+  ])
+  if test "$ac_cv_cxx_stdcxx_tr1" = yes; then
+    AC_DEFINE(STDCXX_TR1_HEADERS,,[Define if ISO C++ TR1 header files are present. ])
+  fi
+])
+
+ +

An alternative is to check just for specific TR1 includes, such as <unordered_map> and <unordered_set>. +

+ +
+# AC_HEADER_TR1_UNORDERED_MAP
+AC_DEFUN([AC_HEADER_TR1_UNORDERED_MAP], [
+  AC_CACHE_CHECK(for tr1/unordered_map,
+  ac_cv_cxx_tr1_unordered_map,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  AC_TRY_COMPILE([#include <tr1/unordered_map>], [using std::tr1::unordered_map;],
+  ac_cv_cxx_tr1_unordered_map=yes, ac_cv_cxx_tr1_unordered_map=no)
+  AC_LANG_RESTORE
+  ])
+  if test "$ac_cv_cxx_tr1_unordered_map" = yes; then
+    AC_DEFINE(HAVE_TR1_UNORDERED_MAP,,[Define if tr1/unordered_map is present. ])
+  fi
+])
+
+ +
+# AC_HEADER_TR1_UNORDERED_SET
+AC_DEFUN([AC_HEADER_TR1_UNORDERED_SET], [
+  AC_CACHE_CHECK(for tr1/unordered_set,
+  ac_cv_cxx_tr1_unordered_set,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  AC_TRY_COMPILE([#include <tr1/unordered_set>], [using std::tr1::unordered_set;],
+  ac_cv_cxx_tr1_unordered_set=yes, ac_cv_cxx_tr1_unordered_set=no)
+  AC_LANG_RESTORE
+  ])
+  if test "$ac_cv_cxx_tr1_unordered_set" = yes; then
+    AC_DEFINE(HAVE_TR1_UNORDERED_SET,,[Define if tr1/unordered_set is present. ])
+  fi
+])
+
+ + + +
+Support for C++0x dialect. +
+ +

Check for baseline language coverage in the compiler for the C++0xstandard. +

+ +
+# AC_COMPILE_STDCXX_OX
+AC_DEFUN([AC_COMPILE_STDCXX_0X], [
+  AC_CACHE_CHECK(if g++ supports C++0x features without additional flags,
+  ac_cv_cxx_compile_cxx0x_native,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  AC_TRY_COMPILE([
+  template <typename T>
+    struct check 
+    {
+      static_assert(sizeof(int) <= sizeof(T), "not big enough");
+    };
+
+    typedef check<check<bool>> right_angle_brackets;
+
+    int a;
+    decltype(a) b;
+
+    typedef check<int> check_type;
+    check_type c;
+    check_type&& cr = c;],,
+  ac_cv_cxx_compile_cxx0x_native=yes, ac_cv_cxx_compile_cxx0x_native=no)
+  AC_LANG_RESTORE
+  ])
+
+  AC_CACHE_CHECK(if g++ supports C++0x features with -std=c++0x,
+  ac_cv_cxx_compile_cxx0x_cxx,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -std=c++0x"	
+  AC_TRY_COMPILE([
+  template <typename T>
+    struct check 
+    {
+      static_assert(sizeof(int) <= sizeof(T), "not big enough");
+    };
+
+    typedef check<check<bool>> right_angle_brackets;
+
+    int a;
+    decltype(a) b;
+
+    typedef check<int> check_type;
+    check_type c;
+    check_type&& cr = c;],,
+  ac_cv_cxx_compile_cxx0x_cxx=yes, ac_cv_cxx_compile_cxx0x_cxx=no)
+  CXXFLAGS="$ac_save_CXXFLAGS"
+  AC_LANG_RESTORE
+  ])
+
+  AC_CACHE_CHECK(if g++ supports C++0x features with -std=gnu++0x,
+  ac_cv_cxx_compile_cxx0x_gxx,
+  [AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -std=gnu++0x"	
+  AC_TRY_COMPILE([
+  template <typename T>
+    struct check 
+    {
+      static_assert(sizeof(int) <= sizeof(T), "not big enough");
+    };
+
+    typedef check<check<bool>> right_angle_brackets;
+
+    int a;
+    decltype(a) b;
+
+    typedef check<int> check_type;
+    check_type c;
+    check_type&& cr = c;],,
+  ac_cv_cxx_compile_cxx0x_gxx=yes, ac_cv_cxx_compile_cxx0x_gxx=no)
+  CXXFLAGS="$ac_save_CXXFLAGS"
+  AC_LANG_RESTORE
+  ])
+
+  if test "$ac_cv_cxx_compile_cxx0x_native" = yes || 
+     test "$ac_cv_cxx_compile_cxx0x_cxx" = yes || 
+     test "$ac_cv_cxx_compile_cxx0x_gxx" = yes; then
+    AC_DEFINE(HAVE_STDCXX_0X,,[Define if g++ supports C++0x features. ])
+  fi
+])
+
+ + +

Check for library coverage of the C++0xstandard. +

+ +
+
+# AC_HEADER_STDCXX_0X
+AC_DEFUN([AC_HEADER_STDCXX_0X], [
+  AC_CACHE_CHECK(for ISO C++ 0x include files,
+  ac_cv_cxx_stdcxx_0x,
+  [AC_REQUIRE([AC_COMPILE_STDCXX_0X])
+  AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -std=gnu++0x"	
+
+  AC_TRY_COMPILE([
+    #include <cassert>
+    #include <ccomplex>
+    #include <cctype>
+    #include <cerrno>
+    #include <cfenv>
+    #include <cfloat>
+    #include <cinttypes>
+    #include <ciso646>
+    #include <climits>
+    #include <clocale>
+    #include <cmath>
+    #include <csetjmp>
+    #include <csignal>
+    #include <cstdarg>
+    #include <cstdbool>
+    #include <cstddef>
+    #include <cstdint>
+    #include <cstdio>
+    #include <cstdlib>
+    #include <cstring>
+    #include <ctgmath>
+    #include <ctime>
+    #include <cwchar>
+    #include <cwctype>
+
+    #include <algorithm>
+    #include <array>
+    #include <bitset>
+    #include <complex>
+    #include <deque>
+    #include <exception>
+    #include <fstream>
+    #include <functional>
+    #include <iomanip>
+    #include <ios>
+    #include <iosfwd>
+    #include <iostream>
+    #include <istream>
+    #include <iterator>
+    #include <limits>
+    #include <list>
+    #include <locale>
+    #include <map>
+    #include <memory>
+    #include <new>
+    #include <numeric>
+    #include <ostream>
+    #include <queue>
+    #include <random>
+    #include <regex>
+    #include <set>
+    #include <sstream>
+    #include <stack>
+    #include <stdexcept>
+    #include <streambuf>
+    #include <string>
+    #include <tuple>
+    #include <typeinfo>
+    #include <type_traits>
+    #include <unordered_map>
+    #include <unordered_set>
+    #include <utility>
+    #include <valarray>
+    #include <vector>
+  ],,
+  ac_cv_cxx_stdcxx_0x=yes, ac_cv_cxx_stdcxx_0x=no)
+  AC_LANG_RESTORE
+  CXXFLAGS="$ac_save_CXXFLAGS"
+  ])
+  if test "$ac_cv_cxx_stdcxx_0x" = yes; then
+    AC_DEFINE(STDCXX_0X_HEADERS,,[Define if ISO C++ 0x header files are present. ])
+  fi
+])
+
+ +

As is the case for TR1 support, these autoconf macros can be made for a finer-grained, per-header-file check. For <unordered_map> +

+ +
+
+# AC_HEADER_UNORDERED_MAP
+AC_DEFUN([AC_HEADER_UNORDERED_MAP], [
+  AC_CACHE_CHECK(for unordered_map,
+  ac_cv_cxx_unordered_map,
+  [AC_REQUIRE([AC_COMPILE_STDCXX_0X])
+  AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -std=gnu++0x"	
+  AC_TRY_COMPILE([#include <unordered_map>], [using std::unordered_map;],
+  ac_cv_cxx_unordered_map=yes, ac_cv_cxx_unordered_map=no)
+  CXXFLAGS="$ac_save_CXXFLAGS"
+  AC_LANG_RESTORE
+  ])
+  if test "$ac_cv_cxx_unordered_map" = yes; then
+    AC_DEFINE(HAVE_UNORDERED_MAP,,[Define if unordered_map is present. ])
+  fi
+])
+
+ +
+# AC_HEADER_UNORDERED_SET
+AC_DEFUN([AC_HEADER_UNORDERED_SET], [
+  AC_CACHE_CHECK(for unordered_set,
+  ac_cv_cxx_unordered_set,
+  [AC_REQUIRE([AC_COMPILE_STDCXX_0X])
+  AC_LANG_SAVE
+  AC_LANG_CPLUSPLUS
+  ac_save_CXXFLAGS="$CXXFLAGS"
+  CXXFLAGS="$CXXFLAGS -std=gnu++0x"	
+  AC_TRY_COMPILE([#include <unordered_set>], [using std::unordered_set;],
+  ac_cv_cxx_unordered_set=yes, ac_cv_cxx_unordered_set=no)
+  CXXFLAGS="$ac_save_CXXFLAGS"
+  AC_LANG_RESTORE
+  ])
+  if test "$ac_cv_cxx_unordered_set" = yes; then
+    AC_DEFINE(HAVE_UNORDERED_SET,,[Define if unordered_set is present. ])
+  fi
+])
+
+ + +
+Container iterator_type is not necessarily container value_type* +
+ + +
+

+ Fourth, and future +

+ +
+

+ Links +

+ +

+Migrating to gcc-4.1, by Dan Kegel. +

+ +

+Building the whole Debian archive with GCC 4.1: a summary, by Martin Michlmayr +

+ +

+Migration guide for GCC-3.2 +

+ + + + -- cgit v1.2.3