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Smart Pointers to boost your code

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27 Sep 2004CPOL13 min read 1.1M   2.5K   227  
A beginner's introduction to the smart pointers provided by the boost library.
//  Boost config.hpp configuration header file  ------------------------------//

//  (C) Copyright John Maddock 2001 - 2003. 
//  (C) Copyright Darin Adler 2001. 
//  (C) Copyright Peter Dimov 2001. 
//  (C) Copyright Bill Kempf 2002. 
//  (C) Copyright Jens Maurer 2002. 
//  (C) Copyright David Abrahams 2002 - 2003. 
//  (C) Copyright Gennaro Prota 2003. 
//  (C) Copyright Eric Friedman 2003. 
//  Use, modification and distribution are subject to the 
//  Boost Software License, Version 1.0. (See accompanying file 
//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

//  See http://www.boost.org for most recent version.

//  Boost config.hpp policy and rationale documentation has been moved to
//  http://www.boost.org/libs/config
//
//  This file is intended to be stable, and relatively unchanging.
//  It should contain boilerplate code only - no compiler specific
//  code unless it is unavoidable - no changes unless unavoidable.

#ifndef BOOST_CONFIG_SUFFIX_HPP
#define BOOST_CONFIG_SUFFIX_HPP

//
// look for long long by looking for the appropriate macros in <limits.h>.
// Note that we use limits.h rather than climits for maximal portability,
// remember that since these just declare a bunch of macros, there should be
// no namespace issues from this.
//
#include <limits.h>
# if !defined(BOOST_HAS_LONG_LONG)                                              \
   && !(defined(BOOST_MSVC) && BOOST_MSVC <=1300) && !defined(__BORLANDC__)     \
   && (defined(ULLONG_MAX) || defined(ULONG_LONG_MAX) || defined(ULONGLONG_MAX))
#  define BOOST_HAS_LONG_LONG
#endif
#if !defined(BOOST_HAS_LONG_LONG) && !defined(BOOST_NO_INTEGRAL_INT64_T)
#  define BOOST_NO_INTEGRAL_INT64_T
#endif

// GCC 3.x will clean up all of those nasty macro definitions that
// BOOST_NO_CTYPE_FUNCTIONS is intended to help work around, so undefine
// it under GCC 3.x.
#if defined(__GNUC__) && (__GNUC__ >= 3) && defined(BOOST_NO_CTYPE_FUNCTIONS)
#  undef BOOST_NO_CTYPE_FUNCTIONS
#endif


//
// Assume any extensions are in namespace std:: unless stated otherwise:
//
#  ifndef BOOST_STD_EXTENSION_NAMESPACE
#    define BOOST_STD_EXTENSION_NAMESPACE std
#  endif

//
// If cv-qualified specializations are not allowed, then neither are cv-void ones:
//
#  if defined(BOOST_NO_CV_SPECIALIZATIONS) \
      && !defined(BOOST_NO_CV_VOID_SPECIALIZATIONS)
#     define BOOST_NO_CV_VOID_SPECIALIZATIONS
#  endif

//
// If there is no numeric_limits template, then it can't have any compile time
// constants either!
//
#  if defined(BOOST_NO_LIMITS) \
      && !defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS)
#     define BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS
#     define BOOST_NO_MS_INT64_NUMERIC_LIMITS
#     define BOOST_NO_LONG_LONG_NUMERIC_LIMITS
#  endif

//
// if there is no long long then there is no specialisation
// for numeric_limits<long long> either:
//
#if !defined(BOOST_HAS_LONG_LONG) && !defined(BOOST_NO_LONG_LONG_NUMERIC_LIMITS)
#  define BOOST_NO_LONG_LONG_NUMERIC_LIMITS
#endif

//
// if there is no __int64 then there is no specialisation
// for numeric_limits<__int64> either:
//
#if !defined(BOOST_HAS_MS_INT64) && !defined(BOOST_NO_MS_INT64_NUMERIC_LIMITS)
#  define BOOST_NO_MS_INT64_NUMERIC_LIMITS
#endif

//
// if member templates are supported then so is the
// VC6 subset of member templates:
//
#  if !defined(BOOST_NO_MEMBER_TEMPLATES) \
       && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)
#     define BOOST_MSVC6_MEMBER_TEMPLATES
#  endif

//
// Without partial specialization, can't test for partial specialisation bugs:
//
#  if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) \
      && !defined(BOOST_BCB_PARTIAL_SPECIALIZATION_BUG)
#     define BOOST_BCB_PARTIAL_SPECIALIZATION_BUG
#  endif

//
// Without partial specialization, we can't have array-type partial specialisations:
//
#  if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) \
      && !defined(BOOST_NO_ARRAY_TYPE_SPECIALIZATIONS)
#     define BOOST_NO_ARRAY_TYPE_SPECIALIZATIONS
#  endif

//
// Without partial specialization, std::iterator_traits can't work:
//
#  if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) \
      && !defined(BOOST_NO_STD_ITERATOR_TRAITS)
#     define BOOST_NO_STD_ITERATOR_TRAITS
#  endif

//
// Without member template support, we can't have template constructors
// in the standard library either:
//
#  if defined(BOOST_NO_MEMBER_TEMPLATES) \
      && !defined(BOOST_MSVC6_MEMBER_TEMPLATES) \
      && !defined(BOOST_NO_TEMPLATED_ITERATOR_CONSTRUCTORS)
#     define BOOST_NO_TEMPLATED_ITERATOR_CONSTRUCTORS
#  endif

//
// Without member template support, we can't have a conforming
// std::allocator template either:
//
#  if defined(BOOST_NO_MEMBER_TEMPLATES) \
      && !defined(BOOST_MSVC6_MEMBER_TEMPLATES) \
      && !defined(BOOST_NO_STD_ALLOCATOR)
#     define BOOST_NO_STD_ALLOCATOR
#  endif

//
// without ADL support then using declarations will break ADL as well:
//
#if defined(BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP) && !defined(BOOST_FUNCTION_SCOPE_USING_DECLARATION_BREAKS_ADL)
#  define BOOST_FUNCTION_SCOPE_USING_DECLARATION_BREAKS_ADL
#endif

//
// If we have a standard allocator, then we have a partial one as well:
//
#if !defined(BOOST_NO_STD_ALLOCATOR)
#  define BOOST_HAS_PARTIAL_STD_ALLOCATOR
#endif

//
// We can't have a working std::use_facet if there is no std::locale:
//
#  if defined(BOOST_NO_STD_LOCALE) && !defined(BOOST_NO_STD_USE_FACET)
#     define BOOST_NO_STD_USE_FACET
#  endif

//
// We can't have a std::messages facet if there is no std::locale:
//
#  if defined(BOOST_NO_STD_LOCALE) && !defined(BOOST_NO_STD_MESSAGES)
#     define BOOST_NO_STD_MESSAGES
#  endif

//
// We can't have a working std::wstreambuf if there is no std::locale:
//
#  if defined(BOOST_NO_STD_LOCALE) && !defined(BOOST_NO_STD_WSTREAMBUF)
#     define BOOST_NO_STD_WSTREAMBUF
#  endif

//
// We can't have a <cwctype> if there is no <cwchar>:
//
#  if defined(BOOST_NO_CWCHAR) && !defined(BOOST_NO_CWCTYPE)
#     define BOOST_NO_CWCTYPE
#  endif

//
// We can't have a swprintf if there is no <cwchar>:
//
#  if defined(BOOST_NO_CWCHAR) && !defined(BOOST_NO_SWPRINTF)
#     define BOOST_NO_SWPRINTF
#  endif

//
// If Win32 support is turned off, then we must turn off
// threading support also, unless there is some other
// thread API enabled:
//
#if defined(BOOST_DISABLE_WIN32) && defined(_WIN32) \
   && !defined(BOOST_DISABLE_THREADS) && !defined(BOOST_HAS_PTHREADS)
#  define BOOST_DISABLE_THREADS
#endif

//
// Turn on threading support if the compiler thinks that it's in
// multithreaded mode.  We put this here because there are only a
// limited number of macros that identify this (if there's any missing
// from here then add to the appropriate compiler section):
//
#if (defined(__MT__) || defined(_MT) || defined(_REENTRANT) \
    || defined(_PTHREADS)) && !defined(BOOST_HAS_THREADS)
#  define BOOST_HAS_THREADS
#endif

//
// Turn threading support off if BOOST_DISABLE_THREADS is defined:
//
#if defined(BOOST_DISABLE_THREADS) && defined(BOOST_HAS_THREADS)
#  undef BOOST_HAS_THREADS
#endif

//
// Turn threading support off if we don't recognise the threading API:
//
#if defined(BOOST_HAS_THREADS) && !defined(BOOST_HAS_PTHREADS)\
      && !defined(BOOST_HAS_WINTHREADS) && !defined(BOOST_HAS_BETHREADS)\
      && !defined(BOOST_HAS_MPTASKS)
#  undef BOOST_HAS_THREADS
#endif

//
// Turn threading detail macros off if we don't (want to) use threading
//
#ifndef BOOST_HAS_THREADS
#  undef BOOST_HAS_PTHREADS
#  undef BOOST_HAS_PTHREAD_MUTEXATTR_SETTYPE
#  undef BOOST_HAS_WINTHREADS
#  undef BOOST_HAS_BETHREADS
#  undef BOOST_HAS_MPTASKS
#endif

//
// If the compiler claims to be C99 conformant, then it had better
// have a <stdint.h>:
//
#  if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901)
#     define BOOST_HAS_STDINT_H
#  endif

//
// Define BOOST_NO_SLIST and BOOST_NO_HASH if required.
// Note that this is for backwards compatibility only.
//
#  ifndef BOOST_HAS_SLIST
#     define BOOST_NO_SLIST
#  endif

#  ifndef BOOST_HAS_HASH
#     define BOOST_NO_HASH
#  endif

//  BOOST_HAS_ABI_HEADERS
//  This macro gets set if we have headers that fix the ABI,
//  and prevent ODR violations when linking to external libraries:
#if defined(BOOST_ABI_PREFIX) && defined(BOOST_ABI_SUFFIX) && !defined(BOOST_HAS_ABI_HEADERS)
#  define BOOST_HAS_ABI_HEADERS
#endif

#if defined(BOOST_HAS_ABI_HEADERS) && defined(BOOST_DISABLE_ABI_HEADERS)
#  undef BOOST_HAS_ABI_HEADERS
#endif

//  BOOST_NO_STDC_NAMESPACE workaround  --------------------------------------//
//  Because std::size_t usage is so common, even in boost headers which do not
//  otherwise use the C library, the <cstddef> workaround is included here so
//  that ugly workaround code need not appear in many other boost headers.
//  NOTE WELL: This is a workaround for non-conforming compilers; <cstddef> 
//  must still be #included in the usual places so that <cstddef> inclusion
//  works as expected with standard conforming compilers.  The resulting
//  double inclusion of <cstddef> is harmless.

# ifdef BOOST_NO_STDC_NAMESPACE
#   include <cstddef>
    namespace std { using ::ptrdiff_t; using ::size_t; }
# endif

//  BOOST_NO_STD_MIN_MAX workaround  -----------------------------------------//

#  ifdef BOOST_NO_STD_MIN_MAX

namespace std {
  template <class _Tp>
  inline const _Tp& min(const _Tp& __a, const _Tp& __b) {
    return __b < __a ? __b : __a;
  }
  template <class _Tp>
  inline const _Tp& max(const _Tp& __a, const _Tp& __b) {
    return  __a < __b ? __b : __a;
  }
}

#  endif

// BOOST_STATIC_CONSTANT workaround --------------------------------------- //
// On compilers which don't allow in-class initialization of static integral
// constant members, we must use enums as a workaround if we want the constants
// to be available at compile-time. This macro gives us a convenient way to
// declare such constants.

#  ifdef BOOST_NO_INCLASS_MEMBER_INITIALIZATION
#       define BOOST_STATIC_CONSTANT(type, assignment) enum { assignment }
#  else
#     define BOOST_STATIC_CONSTANT(type, assignment) static const type assignment
#  endif

// BOOST_USE_FACET workaround ----------------------------------------------//
// When the standard library does not have a conforming std::use_facet there
// are various workarounds available, but they differ from library to library.
// This macro provides a consistent way to access a locale's facets.
// Usage:
//    replace
//       std::use_facet<Type>(loc);
//    with
//       BOOST_USE_FACET(Type, loc);
//    Note do not add a std:: prefix to the front of BOOST_USE_FACET!

#if defined(BOOST_NO_STD_USE_FACET)
#  ifdef BOOST_HAS_TWO_ARG_USE_FACET
#     define BOOST_USE_FACET(Type, loc) std::use_facet(loc, static_cast<Type*>(0))
#  elif defined(BOOST_HAS_MACRO_USE_FACET)
#     define BOOST_USE_FACET(Type, loc) std::_USE(loc, Type)
#  elif defined(BOOST_HAS_STLP_USE_FACET)
#     define BOOST_USE_FACET(Type, loc) (*std::_Use_facet<Type >(loc))
#  endif
#else
#  define BOOST_USE_FACET(Type, loc) std::use_facet< Type >(loc)
#endif

// BOOST_NESTED_TEMPLATE workaround ------------------------------------------//
// Member templates are supported by some compilers even though they can't use
// the A::template member<U> syntax, as a workaround replace:
//
// typedef typename A::template rebind<U> binder;
//
// with:
//
// typedef typename A::BOOST_NESTED_TEMPLATE rebind<U> binder;

#ifndef BOOST_NO_MEMBER_TEMPLATE_KEYWORD
#  define BOOST_NESTED_TEMPLATE template
#else
#  define BOOST_NESTED_TEMPLATE
#endif

// BOOST_UNREACHABLE_RETURN(x) workaround -------------------------------------//
// Normally evaluates to nothing, unless BOOST_NO_UNREACHABLE_RETURN_DETECTION
// is defined, in which case it evaluates to return x; Use when you have a return
// statement that can never be reached.

#ifdef BOOST_NO_UNREACHABLE_RETURN_DETECTION
#  define BOOST_UNREACHABLE_RETURN(x) return x;
#else
#  define BOOST_UNREACHABLE_RETURN(x)
#endif

// BOOST_DEDUCED_TYPENAME workaround ------------------------------------------//
//
// Some compilers don't support the use of `typename' for dependent
// types in deduced contexts, e.g.
//
//     template <class T> void f(T, typename T::type);
//                                  ^^^^^^^^
// Replace these declarations with:
//
//     template <class T> void f(T, BOOST_DEDUCED_TYPENAME T::type);

#ifndef BOOST_NO_DEDUCED_TYPENAME
#  define BOOST_DEDUCED_TYPENAME typename
#else 
#  define BOOST_DEDUCED_TYPENAME
#endif

// BOOST_[APPEND_]EXPLICIT_TEMPLATE_[NON_]TYPE macros --------------------------//
//
// Some compilers have problems with function templates whose
// template parameters don't appear in the function parameter
// list (basically they just link one instantiation of the
// template in the final executable). These macros provide a
// uniform way to cope with the problem with no effects on the
// calling syntax.

// Example:
//
//  #include <iostream>
//  #include <ostream>
//  #include <typeinfo>
//
//  template <int n>
//  void f() { std::cout << n << ' '; }
//
//  template <typename T>
//  void g() { std::cout << typeid(T).name() << ' '; }
//
//  int main() {
//    f<1>();
//    f<2>();
//
//    g<int>();
//    g<double>();
//  }
//
// With VC++ 6.0 the output is:
//
//   2 2 double double
//
// To fix it, write
//
//   template <int n>
//   void f(BOOST_EXPLICIT_TEMPLATE_NON_TYPE(int, n)) { ... }
//
//   template <typename T>
//   void g(BOOST_EXPLICIT_TEMPLATE_TYPE(T)) { ... }
//


#if defined BOOST_NO_EXPLICIT_FUNCTION_TEMPLATE_ARGUMENTS

#  include "boost/type.hpp"
#  include "boost/non_type.hpp"

#  define BOOST_EXPLICIT_TEMPLATE_TYPE(t)         boost::type<t>* = 0
#  define BOOST_EXPLICIT_TEMPLATE_TYPE_SPEC(t)    boost::type<t>*
#  define BOOST_EXPLICIT_TEMPLATE_NON_TYPE(t, v)  boost::non_type<t, v>* = 0
#  define BOOST_EXPLICIT_TEMPLATE_NON_TYPE_SPEC(t, v)  boost::non_type<t, v>*

#  define BOOST_APPEND_EXPLICIT_TEMPLATE_TYPE(t)         \
             , BOOST_EXPLICIT_TEMPLATE_TYPE(t)
#  define BOOST_APPEND_EXPLICIT_TEMPLATE_TYPE_SPEC(t)    \
             , BOOST_EXPLICIT_TEMPLATE_TYPE_SPEC(t)
#  define BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE(t, v)  \
             , BOOST_EXPLICIT_TEMPLATE_NON_TYPE(t, v)
#  define BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE_SPEC(t, v)  \
             , BOOST_EXPLICIT_TEMPLATE_NON_TYPE_SPEC(t, v)

#else

// no workaround needed: expand to nothing

#  define BOOST_EXPLICIT_TEMPLATE_TYPE(t)
#  define BOOST_EXPLICIT_TEMPLATE_TYPE_SPEC(t)
#  define BOOST_EXPLICIT_TEMPLATE_NON_TYPE(t, v)
#  define BOOST_EXPLICIT_TEMPLATE_NON_TYPE_SPEC(t, v)

#  define BOOST_APPEND_EXPLICIT_TEMPLATE_TYPE(t)
#  define BOOST_APPEND_EXPLICIT_TEMPLATE_TYPE_SPEC(t)
#  define BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE(t, v)
#  define BOOST_APPEND_EXPLICIT_TEMPLATE_NON_TYPE_SPEC(t, v)


#endif // defined BOOST_NO_EXPLICIT_FUNCTION_TEMPLATE_ARGUMENTS


// ---------------------------------------------------------------------------//

//
// Helper macro BOOST_STRINGIZE:
// Converts the parameter X to a string after macro replacement
// on X has been performed.
//
#define BOOST_STRINGIZE(X) BOOST_DO_STRINGIZE(X)
#define BOOST_DO_STRINGIZE(X) #X

//
// Helper macro BOOST_JOIN:
// The following piece of macro magic joins the two 
// arguments together, even when one of the arguments is
// itself a macro (see 16.3.1 in C++ standard).  The key
// is that macro expansion of macro arguments does not
// occur in BOOST_DO_JOIN2 but does in BOOST_DO_JOIN.
//
#define BOOST_JOIN( X, Y ) BOOST_DO_JOIN( X, Y )
#define BOOST_DO_JOIN( X, Y ) BOOST_DO_JOIN2(X,Y)
#define BOOST_DO_JOIN2( X, Y ) X##Y

//
// Set some default values for compiler/library/platform names.
// These are for debugging config setup only:
//
#  ifndef BOOST_COMPILER
#     define BOOST_COMPILER "Unknown ISO C++ Compiler"
#  endif
#  ifndef BOOST_STDLIB
#     define BOOST_STDLIB "Unknown ISO standard library"
#  endif
#  ifndef BOOST_PLATFORM
#     if defined(unix) || defined(__unix) || defined(_XOPEN_SOURCE) \
         || defined(_POSIX_SOURCE)
#        define BOOST_PLATFORM "Generic Unix"
#     else
#        define BOOST_PLATFORM "Unknown"
#     endif
#  endif

#endif



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Written By
Klippel
Germany Germany
Peter is tired of being called "Mr. Chen", even so certain individuals insist on it. No, he's not chinese.

Peter has seen lots of boxes you youngsters wouldn't even accept as calculators. He is proud of having visited the insides of a 16 Bit Machine.

In his spare time he ponders new ways of turning groceries into biohazards, or tries to coax South American officials to add some stamps to his passport.

Beyond these trivialities Peter works for Klippel[^], a small german company that wants to make mankind happier by selling them novel loudspeaker measurement equipment.


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