/////////////////////////////////////////////////////////////////////////////// // 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) // #ifndef BOOST_FOREACH // MS compatible compilers support #pragma once #if defined(_MSC_VER) && (_MSC_VER >= 1020) # pragma once #endif #include #include // for std::pair #include #include #if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, <= 1300) \ || defined(__BORLANDC__) && BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x531)) \ || (defined(BOOST_INTEL_CXX_VERSION) && BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION, <= 700) && defined(_MSC_VER))\ || defined(__DECCXX_VER) && BOOST_WORKAROUND(__DECCXX_VER, BOOST_TESTED_AT(60590042)) # define BOOST_FOREACH_NO_LVALUE_RETURN_DETECTION #endif // 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 defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, <= 1300) \ || defined(__BORLANDC__) && BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) \ || (defined(BOOST_INTEL_CXX_VERSION) && BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION, <= 700) && defined(_MSC_VER)) # define BOOST_FOREACH_NO_RVALUE_DETECTION #endif // Some compilers do not correctly implement the L-value/R-value conversion // rules of the ternary conditional operator. #if defined(BOOST_FOREACH_NO_RVALUE_DETECTION) \ || defined(BOOST_NO_SFINAE) \ || defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1400)) \ || defined(BOOST_INTEL_WIN) && BOOST_WORKAROUND(BOOST_INTEL_WIN, BOOST_TESTED_AT(800)) \ || defined(__GNUC__) && BOOST_WORKAROUND(__GNUC__, < 3) \ || (defined(__GNUC__) && BOOST_WORKAROUND(__GNUC__, == 3) && (__GNUC_MINOR__ <= 2)) \ || defined(__IBMCPP__) && BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(600)) \ || defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x570)) # define BOOST_FOREACH_NO_CONST_RVALUE_DETECTION #endif #include #include #include #include #include #include #include #include #ifndef BOOST_FOREACH_NO_CONST_RVALUE_DETECTION # include # include # include # include # include #endif namespace boost { // forward declarations for iterator_range template class iterator_range; // forward declarations for sub_range template class sub_range; namespace foreach { /////////////////////////////////////////////////////////////////////////////// // in_range // template inline std::pair in_range(T begin, T end) { return std::make_pair(begin, end); } } // namespace foreach namespace foreach_detail_ { /////////////////////////////////////////////////////////////////////////////// // adl_begin/adl_end // template inline BOOST_DEDUCED_TYPENAME range_result_iterator::type adl_begin(T &t) { #if defined(__BORLANDC__) && BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) \ || BOOST_WORKAROUND(__GNUC__, < 3) return boost::begin(t); #else using boost::begin; typedef BOOST_DEDUCED_TYPENAME range_result_iterator::type type; return type(begin(t)); #endif } template inline BOOST_DEDUCED_TYPENAME range_result_iterator::type adl_end(T &t) { #if defined(__BORLANDC__) && BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) \ || BOOST_WORKAROUND(__GNUC__, < 3) return boost::end(t); #else using boost::end; typedef BOOST_DEDUCED_TYPENAME range_result_iterator::type type; return type(end(t)); #endif } /////////////////////////////////////////////////////////////////////////////// // auto_any_t/auto_any // 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 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 inline BOOST_DEDUCED_TYPENAME boost::mpl::if_::type &auto_any_cast(auto_any_t a) { return static_cast const &>(a).item; } typedef boost::mpl::true_ const_; /////////////////////////////////////////////////////////////////////////////// // type2type // template struct type2type : boost::mpl::if_ { }; template struct foreach_iterator { typedef BOOST_DEDUCED_TYPENAME boost::mpl::eval_if< C , range_const_iterator , range_iterator >::type type; }; template struct foreach_reference : iterator_reference::type> { }; /////////////////////////////////////////////////////////////////////////////// // encode_type // template inline type2type *encode_type(T &, boost::mpl::false_ *) { return 0; } template inline type2type *encode_type(T const &, boost::mpl::true_ *) { return 0; } /////////////////////////////////////////////////////////////////////////////// // encode_const // template inline boost::is_const *encode_const(T &) { return 0; } #ifndef BOOST_FOREACH_NO_LVALUE_RETURN_DETECTION template inline boost::mpl::true_ *encode_const(T const &) { return 0; } #endif #ifndef BOOST_FOREACH_NO_CONST_RVALUE_DETECTION /////////////////////////////////////////////////////////////////////////////// // rvalue_probe // struct rvalue_probe { template rvalue_probe(T const &t, bool &b) : ptemp(const_cast::type *>(&t)) , rvalue(b) { } template operator U() { rvalue = true; return *static_cast(ptemp); } template operator V &() const { return *static_cast(ptemp); } void *ptemp; bool &rvalue; }; /////////////////////////////////////////////////////////////////////////////// // simple_variant // holds either a T or a T* template struct simple_variant { simple_variant(T *t) : rvalue(false) { *static_cast(data.address()) = t; } simple_variant(T const &t) : rvalue(true) { ::new(data.address()) T(t); } simple_variant(simple_variant const &that) : rvalue(that.rvalue) { if(rvalue) ::new(data.address()) T(*that.get()); else *static_cast(data.address()) = that.get(); } ~simple_variant() { if(rvalue) get()->~T(); } T *get() const { if(rvalue) return static_cast(data.address()); else return *static_cast(data.address()); } private: enum { size = sizeof(T) > sizeof(T*) ? sizeof(T) : sizeof(T*) }; simple_variant &operator =(simple_variant const &); bool const rvalue; mutable aligned_storage data; }; #elif !defined(BOOST_FOREACH_NO_RVALUE_DETECTION) /////////////////////////////////////////////////////////////////////////////// // is_rvalue // template inline boost::mpl::false_ *is_rvalue(T &, int) { return 0; } template inline boost::mpl::true_ *is_rvalue(T const &, ...) { return 0; } #endif // BOOST_FOREACH_NO_CONST_RVALUE_DETECTION /////////////////////////////////////////////////////////////////////////////// // set_false // inline bool set_false(bool &b) { return b = false; } /////////////////////////////////////////////////////////////////////////////// // to_ptr // template inline T *to_ptr(T const &t) { return 0; } // Borland needs a little extra help with arrays #if defined(__BORLANDC__) && BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) template inline T (*to_ptr(T (&t)[N]))[N] { return 0; } #endif /////////////////////////////////////////////////////////////////////////////// // cheap_copy // Overload this for user-defined collection types if they are inexpensive to copy. // This tells BOOST_FOREACH it can avoid the r-value/l-value detection stuff. inline boost::mpl::false_ *cheap_copy(...) { return 0; } template inline boost::mpl::true_ *cheap_copy(std::pair *) { return 0; } template inline boost::mpl::true_ *cheap_copy(iterator_range *) { return 0; } template inline boost::mpl::true_ *cheap_copy(sub_range *) { return 0; } template inline boost::mpl::true_ *cheap_copy(T **) { return 0; } template inline boost::mpl::false_ *cheap_copy(T (*)[N]) { return 0; } /////////////////////////////////////////////////////////////////////////////// // derefof // template 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( *const_cast( reinterpret_cast(t) ) ); } /////////////////////////////////////////////////////////////////////////////// // contain // template inline auto_any contain(T const &t, void *, boost::mpl::true_ *) { return t; } #ifndef BOOST_FOREACH_NO_CONST_RVALUE_DETECTION template inline auto_any contain(T &t, bool *, boost::mpl::false_ *) { return boost::addressof(t); } template inline BOOST_DEDUCED_TYPENAME disable_if< boost::is_array , auto_any > >::type contain(T const &t, bool *rvalue, boost::mpl::false_ *) { return *rvalue ? simple_variant(t) : simple_variant(&t); } #else template inline auto_any contain(T &t, boost::mpl::false_ *, boost::mpl::false_ *) // l-value { return boost::addressof(t); } template inline auto_any contain(T const &t, boost::mpl::true_ *, boost::mpl::false_ *) // r-value { return t; } #endif ///////////////////////////////////////////////////////////////////////////// // begin // template inline auto_any::type> begin(auto_any_t col, type2type *, void *, boost::mpl::true_ *) { return foreach_detail_::adl_begin(auto_any_cast(col)); } #ifndef BOOST_FOREACH_NO_CONST_RVALUE_DETECTION template inline auto_any::type> begin(auto_any_t col, type2type *, bool *, boost::mpl::false_ *) { typedef BOOST_DEDUCED_TYPENAME type2type::type type; return foreach_detail_::adl_begin(derefof(auto_any_cast(col))); } template inline BOOST_DEDUCED_TYPENAME disable_if< boost::is_array , auto_any::type> >::type begin(auto_any_t col, type2type *, bool *, boost::mpl::false_ *) { return foreach_detail_::adl_begin(*auto_any_cast, boost::mpl::false_>(col).get()); } #else template inline auto_any::type> begin(auto_any_t col, type2type *, boost::mpl::false_ *, boost::mpl::false_ *) // l-value { typedef BOOST_DEDUCED_TYPENAME type2type::type type; typedef BOOST_DEDUCED_TYPENAME foreach_iterator::type iterator; return iterator(foreach_detail_::adl_begin(derefof(auto_any_cast(col)))); } template inline auto_any::type> begin(auto_any_t col, type2type *, boost::mpl::true_ *, boost::mpl::false_ *) // r-value { return foreach_detail_::adl_begin(auto_any_cast(col)); } #endif /////////////////////////////////////////////////////////////////////////////// // end // template inline auto_any::type> end(auto_any_t col, type2type *, void *, boost::mpl::true_ *) { return foreach_detail_::adl_end(auto_any_cast(col)); } #ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING template inline auto_any end(auto_any_t col, type2type *, void *, boost::mpl::true_ *) { return 0; // not used } #endif #ifndef BOOST_FOREACH_NO_CONST_RVALUE_DETECTION template inline auto_any::type> end(auto_any_t col, type2type *, bool *, boost::mpl::false_ *) { typedef BOOST_DEDUCED_TYPENAME type2type::type type; return foreach_detail_::adl_end(derefof(auto_any_cast(col))); } template inline BOOST_DEDUCED_TYPENAME disable_if< boost::is_array , auto_any::type> >::type end(auto_any_t col, type2type *, bool *, boost::mpl::false_ *) { return foreach_detail_::adl_end(*auto_any_cast, boost::mpl::false_>(col).get()); } #else template inline auto_any::type> end(auto_any_t col, type2type *, boost::mpl::false_ *, boost::mpl::false_ *) // l-value { typedef BOOST_DEDUCED_TYPENAME type2type::type type; typedef BOOST_DEDUCED_TYPENAME foreach_iterator::type iterator; return iterator(foreach_detail_::adl_end(derefof(auto_any_cast(col)))); } template inline auto_any::type> end(auto_any_t col, type2type *, boost::mpl::true_ *, boost::mpl::false_ *) // r-value { return foreach_detail_::adl_end(auto_any_cast(col)); } #endif /////////////////////////////////////////////////////////////////////////////// // done // template inline bool done(auto_any_t cur, auto_any_t end, type2type *) { typedef BOOST_DEDUCED_TYPENAME foreach_iterator::type iter_t; return auto_any_cast(cur) == auto_any_cast(end); } #ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING template inline bool done(auto_any_t cur, auto_any_t, type2type *) { return ! *auto_any_cast(cur); } #endif /////////////////////////////////////////////////////////////////////////////// // next // template inline void next(auto_any_t cur, type2type *) { typedef BOOST_DEDUCED_TYPENAME foreach_iterator::type iter_t; ++auto_any_cast(cur); } /////////////////////////////////////////////////////////////////////////////// // deref // template inline BOOST_DEDUCED_TYPENAME foreach_reference::type deref(auto_any_t cur, type2type *) { typedef BOOST_DEDUCED_TYPENAME foreach_iterator::type iter_t; return *auto_any_cast(cur); } } // namespace foreach_detail_ } // namespace boost #ifndef BOOST_FOREACH_NO_CONST_RVALUE_DETECTION /////////////////////////////////////////////////////////////////////////////// // R-values and const R-values supported here /////////////////////////////////////////////////////////////////////////////// // 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_::encode_const(COL))) // Evaluate the collection expression, and detect if it is an l-value or and r-value # define BOOST_FOREACH_EVAL(COL) \ (true ? boost::foreach_detail_::rvalue_probe((COL), _foreach_rvalue) : (COL)) // Declare a variable to track the rvalue-ness of the collection expression # define BOOST_FOREACH_DEFINE_RVALUE() \ if (bool _foreach_rvalue = false) {} else // The R-value/L-value-ness of the collection expression is determined dynamically # define BOOST_FOREACH_RVALUE(COL) \ (&_foreach_rvalue) # define BOOST_FOREACH_CHEAP_COPY(COL) \ (true ? 0 : boost::foreach_detail_::cheap_copy(boost::foreach_detail_::to_ptr(COL))) # define BOOST_FOREACH_NOOP(COL) \ ((void)0) #elif !defined(BOOST_FOREACH_NO_RVALUE_DETECTION) /////////////////////////////////////////////////////////////////////////////// // R-values supported here, const R-values NOT supported here /////////////////////////////////////////////////////////////////////////////// // 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_::encode_const(COL))) // Evaluate the collection expression # define BOOST_FOREACH_EVAL(COL) \ (COL) // No variable is needed to track the rvalue-ness of the collection expression # define BOOST_FOREACH_DEFINE_RVALUE() \ /**/ // Determine whether the collection expression is an l-value or an r-value. // NOTE: this gets the answer for const R-values wrong. # define BOOST_FOREACH_RVALUE(COL) \ (true ? 0 : boost::foreach_detail_::is_rvalue((COL), 0)) # define BOOST_FOREACH_CHEAP_COPY(COL) \ (true ? 0 : boost::foreach_detail_::cheap_copy(boost::foreach_detail_::to_ptr(COL))) # define BOOST_FOREACH_NOOP(COL) \ ((void)0) #else /////////////////////////////////////////////////////////////////////////////// // R-values NOT supported here /////////////////////////////////////////////////////////////////////////////// // 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_::encode_const(COL))) // Evaluate the collection expression # define BOOST_FOREACH_EVAL(COL) \ (COL) // No variable is needed to track the rvalue-ness of the collection expression # define BOOST_FOREACH_DEFINE_RVALUE() \ /**/ // Can't use R-values with BOOST_FOREACH # define BOOST_FOREACH_RVALUE(COL) \ (static_cast(0)) # define BOOST_FOREACH_CHEAP_COPY(COL) \ (true ? 0 : boost::foreach_detail_::cheap_copy(boost::foreach_detail_::to_ptr(COL))) // Attempt to make uses of BOOST_FOREACH with non-lvalues fail to compile // BUGBUG but cheap-to-copy containers *would* be handled correctly. Hrm. # define BOOST_FOREACH_NOOP(COL) \ ((void)&(COL)) #endif #define BOOST_FOREACH_CONTAIN(COL) \ boost::foreach_detail_::contain( \ BOOST_FOREACH_EVAL(COL) \ , BOOST_FOREACH_RVALUE(COL) \ , BOOST_FOREACH_CHEAP_COPY(COL)) #define BOOST_FOREACH_BEGIN(COL) \ boost::foreach_detail_::begin( \ _foreach_col \ , BOOST_FOREACH_TYPEOF(COL) \ , BOOST_FOREACH_RVALUE(COL) \ , BOOST_FOREACH_CHEAP_COPY(COL)) #define BOOST_FOREACH_END(COL) \ boost::foreach_detail_::end( \ _foreach_col \ , BOOST_FOREACH_TYPEOF(COL) \ , BOOST_FOREACH_RVALUE(COL) \ , BOOST_FOREACH_CHEAP_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_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_DEFINE_RVALUE() \ 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) : BOOST_FOREACH_NOOP(COL)) \ if (boost::foreach_detail_::set_false(_foreach_continue)) {} else \ for (VAR = BOOST_FOREACH_DEREF(COL); !_foreach_continue; _foreach_continue = true) #define foreach BOOST_FOREACH #endif