///////////////////////////////////////////////////////////////////////////////
// foreach.hpp header file
//
// Copyright 2004 Eric Niebler.
// Distributed under 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)
//
// Credits:
// Anson Tsao - for the initial inspiration and several good suggestions.
// Thorsten Ottosen - for Boost.Range, and for suggesting a way to detect
// const-qualified rvalues at compile time on VC7.1+
// Russell Hind - For help porting to Borland
// Alisdair Meredith - For help porting to Borland
// Stefan Slapeta - For help porting to Intel
#ifndef BOOST_FOREACH
// MS compatible compilers support #pragma once
#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif
#include <cstddef>
#include <utility> // for std::pair
#include <boost/config.hpp>
#include <boost/detail/workaround.hpp>
// Some compilers let us detect even const-qualified rvalues at compile-time
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1310) \
|| (BOOST_WORKAROUND(__GNUC__, >= 4) && !defined(BOOST_INTEL)) \
|| (BOOST_WORKAROUND(__GNUC__, == 3) && (__GNUC_MINOR__ >= 4) && !defined(BOOST_INTEL))
# define BOOST_FOREACH_COMPILE_TIME_CONST_RVALUE_DETECTION
#else
// Some compilers allow temporaries to be bound to non-const references.
// These compilers make it impossible to for BOOST_FOREACH to detect
// temporaries and avoid reevaluation of the collection expression.
# if BOOST_WORKAROUND(BOOST_MSVC, <= 1300) \
|| BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) \
|| (BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION, <= 700) && defined(_MSC_VER)) \
|| BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x570)) \
|| BOOST_WORKAROUND(__DECCXX_VER, BOOST_TESTED_AT(60590042))
# define BOOST_FOREACH_NO_RVALUE_DETECTION
# endif
// Some compilers do not correctly implement the lvalue/rvalue conversion
// rules of the ternary conditional operator.
# if defined(BOOST_FOREACH_NO_RVALUE_DETECTION) \
|| defined(BOOST_NO_SFINAE) \
|| BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1400)) \
|| BOOST_WORKAROUND(BOOST_INTEL_WIN, <= 810) \
|| BOOST_WORKAROUND(__GNUC__, < 3) \
|| (BOOST_WORKAROUND(__GNUC__, == 3) && (__GNUC_MINOR__ <= 2)) \
|| (BOOST_WORKAROUND(__GNUC__, == 3) && (__GNUC_MINOR__ <= 3) && defined(__APPLE_CC__)) \
|| BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(600)) \
|| BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3206))
# define BOOST_FOREACH_NO_CONST_RVALUE_DETECTION
# else
# define BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION
# endif
#endif
#include <boost/mpl/if.hpp>
#include <boost/mpl/logical.hpp>
#include <boost/mpl/eval_if.hpp>
#include <boost/noncopyable.hpp>
#include <boost/range/end.hpp>
#include <boost/range/begin.hpp>
#include <boost/range/result_iterator.hpp>
#include <boost/type_traits/is_array.hpp>
#include <boost/type_traits/is_const.hpp>
#include <boost/type_traits/is_abstract.hpp>
#include <boost/type_traits/is_base_and_derived.hpp>
#include <boost/iterator/iterator_traits.hpp>
#include <boost/utility/addressof.hpp>
#ifdef BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION
# include <new>
# include <boost/aligned_storage.hpp>
# include <boost/utility/enable_if.hpp>
# include <boost/type_traits/remove_const.hpp>
#endif
// This must be at global scope, hence the uglified name
enum boost_foreach_argument_dependent_lookup_hack
{
boost_foreach_argument_dependent_lookup_hack_value
};
namespace boost
{
// forward declarations for iterator_range
template<typename T>
class iterator_range;
// forward declarations for sub_range
template<typename T>
class sub_range;
namespace foreach
{
///////////////////////////////////////////////////////////////////////////////
// in_range
//
template<typename T>
inline std::pair<T, T> in_range(T begin, T end)
{
return std::make_pair(begin, end);
}
///////////////////////////////////////////////////////////////////////////////
// boost::foreach::tag
//
typedef boost_foreach_argument_dependent_lookup_hack tag;
///////////////////////////////////////////////////////////////////////////////
// boost::foreach::is_lightweight_proxy
// Specialize this for user-defined collection types if they are inexpensive to copy.
// This tells BOOST_FOREACH it can avoid the rvalue/lvalue detection stuff.
template<typename T>
struct is_lightweight_proxy
: boost::mpl::false_
{
};
///////////////////////////////////////////////////////////////////////////////
// boost::foreach::is_noncopyable
// Specialize this for user-defined collection types if they cannot be copied.
// This also tells BOOST_FOREACH to avoid the rvalue/lvalue detection stuff.
template<typename T>
struct is_noncopyable
#if !defined(BOOST_BROKEN_IS_BASE_AND_DERIVED) && !defined(BOOST_NO_IS_ABSTRACT)
: boost::mpl::or_<
boost::is_abstract<T>
, boost::is_base_and_derived<boost::noncopyable, T>
>
#elif !defined(BOOST_BROKEN_IS_BASE_AND_DERIVED)
: boost::is_base_and_derived<boost::noncopyable, T>
#elif !defined(BOOST_NO_IS_ABSTRACT)
: boost::is_abstract<T>
#else
: boost::mpl::false_
#endif
{
};
} // namespace foreach
} // namespace boost
// vc6/7 needs help ordering the following overloads
#ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
# define BOOST_FOREACH_TAG_DEFAULT ...
#else
# define BOOST_FOREACH_TAG_DEFAULT boost::foreach::tag
#endif
///////////////////////////////////////////////////////////////////////////////
// boost_foreach_is_lightweight_proxy
// Another customization point for the is_lightweight_proxy optimization,
// this one works on legacy compilers. Overload boost_foreach_is_lightweight_proxy
// at the global namespace for your type.
template<typename T>
inline boost::foreach::is_lightweight_proxy<T> *
boost_foreach_is_lightweight_proxy(T *&, BOOST_FOREACH_TAG_DEFAULT) { return 0; }
template<typename T>
inline boost::mpl::true_ *
boost_foreach_is_lightweight_proxy(std::pair<T, T> *&, boost::foreach::tag) { return 0; }
template<typename T>
inline boost::mpl::true_ *
boost_foreach_is_lightweight_proxy(boost::iterator_range<T> *&, boost::foreach::tag) { return 0; }
template<typename T>
inline boost::mpl::true_ *
boost_foreach_is_lightweight_proxy(boost::sub_range<T> *&, boost::foreach::tag) { return 0; }
template<typename T>
inline boost::mpl::true_ *
boost_foreach_is_lightweight_proxy(T **&, boost::foreach::tag) { return 0; }
///////////////////////////////////////////////////////////////////////////////
// boost_foreach_is_noncopyable
// Another customization point for the is_noncopyable trait,
// this one works on legacy compilers. Overload boost_foreach_is_noncopyable
// at the global namespace for your type.
template<typename T>
inline boost::foreach::is_noncopyable<T> *
boost_foreach_is_noncopyable(T *&, BOOST_FOREACH_TAG_DEFAULT) { return 0; }
namespace boost
{
namespace foreach_detail_
{
///////////////////////////////////////////////////////////////////////////////
// Define some utilities for assessing the properties of expressions
//
typedef char yes_type;
typedef char (&no_type)[2];
yes_type is_true(boost::mpl::true_ *);
no_type is_true(boost::mpl::false_ *);
// Extracts the desired property from the expression without evaluating it
#define BOOST_FOREACH_PROTECT(expr) \
(static_cast<boost::mpl::bool_<1 == sizeof(boost::foreach_detail_::is_true(expr))> *>(0))
template<typename Bool1, typename Bool2>
inline boost::mpl::and_<Bool1, Bool2> *and_(Bool1 *, Bool2 *) { return 0; }
template<typename Bool1, typename Bool2, typename Bool3>
inline boost::mpl::and_<Bool1, Bool2, Bool3> *and_(Bool1 *, Bool2 *, Bool3 *) { return 0; }
template<typename Bool1, typename Bool2>
inline boost::mpl::or_<Bool1, Bool2> *or_(Bool1 *, Bool2 *) { return 0; }
template<typename Bool1, typename Bool2, typename Bool3>
inline boost::mpl::or_<Bool1, Bool2, Bool3> *or_(Bool1 *, Bool2 *, Bool3 *) { return 0; }
template<typename Bool>
inline boost::mpl::not_<Bool> *not_(Bool *) { return 0; }
template<typename T>
inline boost::mpl::false_ *is_rvalue_(T &, int) { return 0; }
template<typename T>
inline boost::mpl::true_ *is_rvalue_(T const &, ...) { return 0; }
template<typename T>
inline boost::is_array<T> *is_array_(T const &) { return 0; }
template<typename T>
inline boost::is_const<T> *is_const_(T &) { return 0; }
#ifndef BOOST_FOREACH_NO_RVALUE_DETECTION
template<typename T>
inline boost::mpl::true_ *is_const_(T const &) { return 0; }
#endif
///////////////////////////////////////////////////////////////////////////////
// auto_any_t/auto_any
// General utility for putting an object of any type into automatic storage
struct auto_any_base
{
// auto_any_base must evaluate to false in boolean context so that
// they can be declared in if() statements.
operator bool() const
{
return false;
}
};
template<typename T>
struct auto_any : auto_any_base
{
auto_any(T const &t)
: item(t)
{
}
// temporaries of type auto_any will be bound to const auto_any_base
// references, but we still want to be able to mutate the stored
// data, so declare it as mutable.
mutable T item;
};
typedef auto_any_base const &auto_any_t;
template<typename T, typename C>
inline BOOST_DEDUCED_TYPENAME boost::mpl::if_<C, T const, T>::type &auto_any_cast(auto_any_t a)
{
return static_cast<auto_any<T> const &>(a).item;
}
typedef boost::mpl::true_ const_;
///////////////////////////////////////////////////////////////////////////////
// type2type
//
template<typename T, typename C = boost::mpl::false_>
struct type2type
: boost::mpl::if_<C, T const, T>
{
};
template<typename T, typename C = boost::mpl::false_>
struct foreach_iterator
{
typedef BOOST_DEDUCED_TYPENAME boost::mpl::eval_if<
C
, range_const_iterator<T>
, range_iterator<T>
>::type type;
};
template<typename T, typename C = boost::mpl::false_>
struct foreach_reference
: iterator_reference<BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type>
{
};
///////////////////////////////////////////////////////////////////////////////
// encode_type
//
template<typename T>
inline type2type<T> *encode_type(T &, boost::mpl::false_ *) { return 0; }
template<typename T>
inline type2type<T, const_> *encode_type(T const &, boost::mpl::true_ *) { return 0; }
///////////////////////////////////////////////////////////////////////////////
// set_false
//
inline bool set_false(bool &b) { return b = false; }
///////////////////////////////////////////////////////////////////////////////
// to_ptr
//
template<typename T>
inline T *&to_ptr(T const &)
{
static T *t = 0;
return t;
}
// Borland needs a little extra help with arrays
#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
template<typename T,std::size_t N>
inline T (*&to_ptr(T (&)[N]))[N]
{
static T (*t)[N] = 0;
return t;
}
#endif
///////////////////////////////////////////////////////////////////////////////
// derefof
//
template<typename T>
inline T &derefof(T *t)
{
// This is a work-around for a compiler bug in Borland. If T* is a pointer to array type U(*)[N],
// then dereferencing it results in a U* instead of U(&)[N]. The cast forces the issue.
return reinterpret_cast<T &>(
*const_cast<char *>(
reinterpret_cast<char const volatile *>(t)
)
);
}
#ifdef BOOST_FOREACH_COMPILE_TIME_CONST_RVALUE_DETECTION
///////////////////////////////////////////////////////////////////////////////
// Detect at compile-time whether an expression yields an rvalue or
// an lvalue. This is rather non-standard, but some popular compilers
// accept it.
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
// rvalue_probe
//
template<typename T>
struct rvalue_probe
{
struct private_type_ {};
// can't ever return an array by value
typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_<
boost::mpl::or_<boost::is_abstract<T>, boost::is_array<T> >, private_type_, T
>::type value_type;
operator value_type();
operator T &() const;
};
template<typename T>
rvalue_probe<T> const make_probe(T const &t);
# define BOOST_FOREACH_IS_RVALUE(COL) \
boost::foreach_detail_::and_( \
boost::foreach_detail_::not_(boost::foreach_detail_::is_array_(COL)) \
, BOOST_FOREACH_PROTECT(boost::foreach_detail_::is_rvalue_( \
(true ? boost::foreach_detail_::make_probe(COL) : (COL)), 0)))
#elif defined(BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION)
///////////////////////////////////////////////////////////////////////////////
// Detect at run-time whether an expression yields an rvalue
// or an lvalue. This is 100% standard C++, but not all compilers
// accept it. Also, it causes FOREACH to break when used with non-
// copyable collection types.
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
// rvalue_probe
//
template<typename T>
struct rvalue_probe
{
rvalue_probe(T &t, bool &b)
: value(t)
, is_rvalue(b)
{
}
struct private_type_ {};
// can't ever return an array or an abstract type by value
#ifdef BOOST_NO_IS_ABSTRACT
typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_<
boost::is_array<T>, private_type_, T
>::type value_type;
#else
typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_<
boost::mpl::or_<boost::is_abstract<T>, boost::is_array<T> >, private_type_, T
>::type value_type;
#endif
operator value_type()
{
this->is_rvalue = true;
return this->value;
}
operator T &() const
{
return this->value;
}
private:
T &value;
bool &is_rvalue;
};
template<typename T>
rvalue_probe<T> make_probe(T &t, bool &b) { return rvalue_probe<T>(t, b); }
template<typename T>
rvalue_probe<T const> make_probe(T const &t, bool &b) { return rvalue_probe<T const>(t, b); }
///////////////////////////////////////////////////////////////////////////////
// simple_variant
// holds either a T or a T const*
template<typename T>
struct simple_variant
{
simple_variant(T const *t)
: is_rvalue(false)
{
*static_cast<T const **>(this->data.address()) = t;
}
simple_variant(T const &t)
: is_rvalue(true)
{
::new(this->data.address()) T(t);
}
simple_variant(simple_variant const &that)
: is_rvalue(that.is_rvalue)
{
if(this->is_rvalue)
::new(this->data.address()) T(*that.get());
else
*static_cast<T const **>(this->data.address()) = that.get();
}
~simple_variant()
{
if(this->is_rvalue)
this->get()->~T();
}
T const *get() const
{
if(this->is_rvalue)
return static_cast<T const *>(this->data.address());
else
return *static_cast<T const * const *>(this->data.address());
}
private:
enum size_type { size = sizeof(T) > sizeof(T*) ? sizeof(T) : sizeof(T*) };
simple_variant &operator =(simple_variant const &);
bool const is_rvalue;
aligned_storage<size> data;
};
// If the collection is an array or is noncopyable, it must be an lvalue.
// If the collection is a lightweight proxy, treat it as an rvalue
// BUGBUG what about a noncopyable proxy?
template<typename LValue, typename IsProxy>
inline BOOST_DEDUCED_TYPENAME boost::enable_if<boost::mpl::or_<LValue, IsProxy>, IsProxy>::type *
should_copy_impl(LValue *, IsProxy *, bool *)
{
return 0;
}
// Otherwise, we must determine at runtime whether it's an lvalue or rvalue
inline bool *
should_copy_impl(boost::mpl::false_ *, boost::mpl::false_ *, bool *is_rvalue)
{
return is_rvalue;
}
#endif
///////////////////////////////////////////////////////////////////////////////
// contain
//
template<typename T>
inline auto_any<T> contain(T const &t, boost::mpl::true_ *) // rvalue
{
return t;
}
template<typename T>
inline auto_any<T *> contain(T &t, boost::mpl::false_ *) // lvalue
{
// Cannot seem to get sunpro to handle addressof() with array types.
#if BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x570))
return &t;
#else
return boost::addressof(t);
#endif
}
#ifdef BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION
template<typename T>
auto_any<simple_variant<T> >
contain(T const &t, bool *rvalue)
{
return *rvalue ? simple_variant<T>(t) : simple_variant<T>(&t);
}
#endif
/////////////////////////////////////////////////////////////////////////////
// begin
//
template<typename T, typename C>
inline auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type>
begin(auto_any_t col, type2type<T, C> *, boost::mpl::true_ *) // rvalue
{
return boost::begin(auto_any_cast<T, C>(col));
}
template<typename T, typename C>
inline auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type>
begin(auto_any_t col, type2type<T, C> *, boost::mpl::false_ *) // lvalue
{
typedef BOOST_DEDUCED_TYPENAME type2type<T, C>::type type;
typedef BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type iterator;
return iterator(boost::begin(derefof(auto_any_cast<type *, boost::mpl::false_>(col))));
}
#ifdef BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION
template<typename T>
auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, const_>::type>
begin(auto_any_t col, type2type<T, const_> *, bool *)
{
return boost::begin(*auto_any_cast<simple_variant<T>, boost::mpl::false_>(col).get());
}
#endif
///////////////////////////////////////////////////////////////////////////////
// end
//
template<typename T, typename C>
inline auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type>
end(auto_any_t col, type2type<T, C> *, boost::mpl::true_ *) // rvalue
{
return boost::end(auto_any_cast<T, C>(col));
}
template<typename T, typename C>
inline auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type>
end(auto_any_t col, type2type<T, C> *, boost::mpl::false_ *) // lvalue
{
typedef BOOST_DEDUCED_TYPENAME type2type<T, C>::type type;
typedef BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type iterator;
return iterator(boost::end(derefof(auto_any_cast<type *, boost::mpl::false_>(col))));
}
#ifdef BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION
template<typename T>
auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, const_>::type>
end(auto_any_t col, type2type<T, const_> *, bool *)
{
return boost::end(*auto_any_cast<simple_variant<T>, boost::mpl::false_>(col).get());
}
#endif
#ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
template<typename T, typename C>
inline auto_any<int>
end(auto_any_t col, type2type<T *, C> *, boost::mpl::true_ *) // null-terminated C-style strings
{
return 0; // not used
}
#endif
///////////////////////////////////////////////////////////////////////////////
// done
//
template<typename T, typename C>
inline bool done(auto_any_t cur, auto_any_t end, type2type<T, C> *)
{
typedef BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type iter_t;
return auto_any_cast<iter_t, boost::mpl::false_>(cur) == auto_any_cast<iter_t, boost::mpl::false_>(end);
}
#ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
template<typename T, typename C>
inline bool done(auto_any_t cur, auto_any_t, type2type<T *, C> *) // null-terminated C-style strings
{
return ! *auto_any_cast<T *, boost::mpl::false_>(cur);
}
#endif
///////////////////////////////////////////////////////////////////////////////
// next
//
template<typename T, typename C>
inline void next(auto_any_t cur, type2type<T, C> *)
{
typedef BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type iter_t;
++auto_any_cast<iter_t, boost::mpl::false_>(cur);
}
///////////////////////////////////////////////////////////////////////////////
// deref
//
template<typename T, typename C>
inline BOOST_DEDUCED_TYPENAME foreach_reference<T, C>::type
deref(auto_any_t cur, type2type<T, C> *)
{
typedef BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type iter_t;
return *auto_any_cast<iter_t, boost::mpl::false_>(cur);
}
} // namespace foreach_detail_
} // namespace boost
// A sneaky way to get the type of the collection without evaluating the expression
#define BOOST_FOREACH_TYPEOF(COL) \
(true ? 0 : boost::foreach_detail_::encode_type(COL, boost::foreach_detail_::is_const_(COL)))
// returns true_* if the type is noncopyable
#define BOOST_FOREACH_IS_NONCOPYABLE(COL) \
boost_foreach_is_noncopyable( \
boost::foreach_detail_::to_ptr(COL) \
, boost_foreach_argument_dependent_lookup_hack_value)
// returns true_* if the type is a lightweight proxy (and is not noncopyable)
#define BOOST_FOREACH_IS_LIGHTWEIGHT_PROXY(COL) \
boost::foreach_detail_::and_( \
boost::foreach_detail_::not_(BOOST_FOREACH_IS_NONCOPYABLE(COL)) \
, boost_foreach_is_lightweight_proxy( \
boost::foreach_detail_::to_ptr(COL) \
, boost_foreach_argument_dependent_lookup_hack_value))
#ifdef BOOST_FOREACH_COMPILE_TIME_CONST_RVALUE_DETECTION
///////////////////////////////////////////////////////////////////////////////
// R-values and const R-values supported here with zero runtime overhead
///////////////////////////////////////////////////////////////////////////////
// No variable is needed to track the rvalue-ness of the collection expression
# define BOOST_FOREACH_PREAMBLE() \
/**/
// Evaluate the collection expression
# define BOOST_FOREACH_EVALUATE(COL) \
(COL)
# define BOOST_FOREACH_SHOULD_COPY(COL) \
(true ? 0 : boost::foreach_detail_::or_( \
BOOST_FOREACH_IS_RVALUE(COL) \
, BOOST_FOREACH_IS_LIGHTWEIGHT_PROXY(COL)))
#elif defined(BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION)
///////////////////////////////////////////////////////////////////////////////
// R-values and const R-values supported here
///////////////////////////////////////////////////////////////////////////////
// Declare a variable to track the rvalue-ness of the collection expression
# define BOOST_FOREACH_PREAMBLE() \
if (bool _foreach_is_rvalue = false) {} else
// Evaluate the collection expression, and detect if it is an lvalue or and rvalue
# define BOOST_FOREACH_EVALUATE(COL) \
(true ? boost::foreach_detail_::make_probe((COL), _foreach_is_rvalue) : (COL))
// The rvalue/lvalue-ness of the collection expression is determined dynamically, unless
// type type is an array or is noncopyable or is non-const, in which case we know it's an lvalue.
// If the type happens to be a lightweight proxy, always make a copy.
# define BOOST_FOREACH_SHOULD_COPY(COL) \
(boost::foreach_detail_::should_copy_impl( \
true ? 0 : boost::foreach_detail_::or_( \
boost::foreach_detail_::is_array_(COL) \
, BOOST_FOREACH_IS_NONCOPYABLE(COL) \
, boost::foreach_detail_::not_(boost::foreach_detail_::is_const_(COL))) \
, true ? 0 : BOOST_FOREACH_IS_LIGHTWEIGHT_PROXY(COL) \
, &_foreach_is_rvalue))
#elif !defined(BOOST_FOREACH_NO_RVALUE_DETECTION)
///////////////////////////////////////////////////////////////////////////////
// R-values supported here, const R-values NOT supported here
///////////////////////////////////////////////////////////////////////////////
// No variable is needed to track the rvalue-ness of the collection expression
# define BOOST_FOREACH_PREAMBLE() \
/**/
// Evaluate the collection expression
# define BOOST_FOREACH_EVALUATE(COL) \
(COL)
// Determine whether the collection expression is an lvalue or an rvalue.
// NOTE: this gets the answer wrong for const rvalues.
# define BOOST_FOREACH_SHOULD_COPY(COL) \
(true ? 0 : boost::foreach_detail_::or_( \
boost::foreach_detail_::is_rvalue_((COL), 0) \
, BOOST_FOREACH_IS_LIGHTWEIGHT_PROXY(COL)))
#else
///////////////////////////////////////////////////////////////////////////////
// R-values NOT supported here
///////////////////////////////////////////////////////////////////////////////
// No variable is needed to track the rvalue-ness of the collection expression
# define BOOST_FOREACH_PREAMBLE() \
/**/
// Evaluate the collection expression
# define BOOST_FOREACH_EVALUATE(COL) \
(COL)
// Can't use rvalues with BOOST_FOREACH (unless they are lightweight proxies)
# define BOOST_FOREACH_SHOULD_COPY(COL) \
(true ? 0 : BOOST_FOREACH_IS_LIGHTWEIGHT_PROXY(COL))
#endif
#define BOOST_FOREACH_CONTAIN(COL) \
boost::foreach_detail_::contain( \
BOOST_FOREACH_EVALUATE(COL) \
, BOOST_FOREACH_SHOULD_COPY(COL))
#define BOOST_FOREACH_BEGIN(COL) \
boost::foreach_detail_::begin( \
_foreach_col \
, BOOST_FOREACH_TYPEOF(COL) \
, BOOST_FOREACH_SHOULD_COPY(COL))
#define BOOST_FOREACH_END(COL) \
boost::foreach_detail_::end( \
_foreach_col \
, BOOST_FOREACH_TYPEOF(COL) \
, BOOST_FOREACH_SHOULD_COPY(COL))
#define BOOST_FOREACH_DONE(COL) \
boost::foreach_detail_::done( \
_foreach_cur \
, _foreach_end \
, BOOST_FOREACH_TYPEOF(COL))
#define BOOST_FOREACH_NEXT(COL) \
boost::foreach_detail_::next( \
_foreach_cur \
, BOOST_FOREACH_TYPEOF(COL))
#define BOOST_FOREACH_DEREF(COL) \
boost::foreach_detail_::deref( \
_foreach_cur \
, BOOST_FOREACH_TYPEOF(COL))
///////////////////////////////////////////////////////////////////////////////
// BOOST_FOREACH
//
// For iterating over collections. Collections can be
// arrays, null-terminated strings, or STL containers.
// The loop variable can be a value or reference. For
// example:
//
// std::list<int> int_list(/*stuff*/);
// BOOST_FOREACH(int &i, int_list)
// {
// /*
// * loop body goes here.
// * i is a reference to the int in int_list.
// */
// }
//
// Alternately, you can declare the loop variable first,
// so you can access it after the loop finishes. Obviously,
// if you do it this way, then the loop variable cannot be
// a reference.
//
// int i;
// BOOST_FOREACH(i, int_list)
// { ... }
//
#define BOOST_FOREACH(VAR, COL) \
BOOST_FOREACH_PREAMBLE() \
if (boost::foreach_detail_::auto_any_t _foreach_col = BOOST_FOREACH_CONTAIN(COL)) {} else \
if (boost::foreach_detail_::auto_any_t _foreach_cur = BOOST_FOREACH_BEGIN(COL)) {} else \
if (boost::foreach_detail_::auto_any_t _foreach_end = BOOST_FOREACH_END(COL)) {} else \
for (bool _foreach_continue = true; \
_foreach_continue && !BOOST_FOREACH_DONE(COL); \
_foreach_continue ? BOOST_FOREACH_NEXT(COL) : (void)0) \
if (boost::foreach_detail_::set_false(_foreach_continue)) {} else \
for (VAR = BOOST_FOREACH_DEREF(COL); !_foreach_continue; _foreach_continue = true)
#endif