diff options
Diffstat (limited to 'indra/llcommon/llstl.h')
| -rwxr-xr-x[-rw-r--r--] | indra/llcommon/llstl.h | 288 |
1 files changed, 261 insertions, 27 deletions
diff --git a/indra/llcommon/llstl.h b/indra/llcommon/llstl.h index 788617953e..02f10fa2ba 100644..100755 --- a/indra/llcommon/llstl.h +++ b/indra/llcommon/llstl.h @@ -2,31 +2,25 @@ * @file llstl.h * @brief helper object & functions for use with the stl. * - * $LicenseInfo:firstyear=2003&license=viewergpl$ - * - * Copyright (c) 2003-2009, Linden Research, Inc. - * + * $LicenseInfo:firstyear=2003&license=viewerlgpl$ * Second Life Viewer Source Code - * The source code in this file ("Source Code") is provided by Linden Lab - * to you under the terms of the GNU General Public License, version 2.0 - * ("GPL"), unless you have obtained a separate licensing agreement - * ("Other License"), formally executed by you and Linden Lab. Terms of - * the GPL can be found in doc/GPL-license.txt in this distribution, or - * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2 + * Copyright (C) 2010, Linden Research, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License only. * - * There are special exceptions to the terms and conditions of the GPL as - * it is applied to this Source Code. View the full text of the exception - * in the file doc/FLOSS-exception.txt in this software distribution, or - * online at - * http://secondlifegrid.net/programs/open_source/licensing/flossexception + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. * - * By copying, modifying or distributing this software, you acknowledge - * that you have read and understood your obligations described above, - * and agree to abide by those obligations. + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * - * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO - * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY, - * COMPLETENESS OR PERFORMANCE. + * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ @@ -37,8 +31,9 @@ #include <algorithm> #include <map> #include <vector> +#include <list> #include <set> -#include <deque> +#include <typeinfo> // Use to compare the first element only of a pair // e.g. typedef std::set<std::pair<int, Data*>, compare_pair<int, Data*> > some_pair_set_t; @@ -103,6 +98,7 @@ struct DeletePointerArray // The general form is: // // std::for_each(somemap.begin(), somemap.end(), DeletePairedPointer()); +// somemap.clear(); // Don't leave dangling pointers around struct DeletePairedPointer { @@ -129,7 +125,7 @@ struct DeletePairedPointerArray // compiler, the second unary_function template parameter can be set // to void. // -// Here's a snippit showing how you use this object: +// Here's a snippet showing how you use this object: // // typedef std::map<int, widget*> map_type; // map_type widget_map; @@ -174,6 +170,49 @@ struct CopyNewPointer } }; +template<typename T, typename ALLOC> +void delete_and_clear(std::list<T*, ALLOC>& list) +{ + std::for_each(list.begin(), list.end(), DeletePointer()); + list.clear(); +} + +template<typename T, typename ALLOC> +void delete_and_clear(std::vector<T*, ALLOC>& vector) +{ + std::for_each(vector.begin(), vector.end(), DeletePointer()); + vector.clear(); +} + +template<typename T, typename COMPARE, typename ALLOC> +void delete_and_clear(std::set<T*, COMPARE, ALLOC>& set) +{ + std::for_each(set.begin(), set.end(), DeletePointer()); + set.clear(); +} + +template<typename K, typename V, typename COMPARE, typename ALLOC> +void delete_and_clear(std::map<K, V*, COMPARE, ALLOC>& map) +{ + std::for_each(map.begin(), map.end(), DeletePairedPointer()); + map.clear(); +} + +template<typename T> +void delete_and_clear(T*& ptr) +{ + delete ptr; + ptr = NULL; +} + + +template<typename T> +void delete_and_clear_array(T*& ptr) +{ + delete[] ptr; + ptr = NULL; +} + // Simple function to help with finding pointers in maps. // For example: // typedef map_t; @@ -233,7 +272,6 @@ inline T get_if_there(const std::map<K,T>& inmap, const K& key, T default_value) } }; -// Useful for replacing the removeObj() functionality of LLDynamicArray // Example: // for (std::vector<T>::iterator iter = mList.begin(); iter != mList.end(); ) // { @@ -242,8 +280,8 @@ inline T get_if_there(const std::map<K,T>& inmap, const K& key, T default_value) // else // ++iter; // } -template <typename T, typename Iter> -inline Iter vector_replace_with_last(std::vector<T>& invec, Iter iter) +template <typename T> +inline typename std::vector<T>::iterator vector_replace_with_last(std::vector<T>& invec, typename std::vector<T>::iterator iter) { typename std::vector<T>::iterator last = invec.end(); --last; if (iter == invec.end()) @@ -263,7 +301,6 @@ inline Iter vector_replace_with_last(std::vector<T>& invec, Iter iter) } }; -// Useful for replacing the removeObj() functionality of LLDynamicArray // Example: // vector_replace_with_last(mList, x); template <typename T> @@ -476,4 +513,201 @@ llbind2nd(const _Operation& __oper, const _Tp& __x) return llbinder2nd<_Operation>(__oper, _Arg2_type(__x)); } +/** + * Compare std::type_info* pointers a la std::less. We break this out as a + * separate function for use in two different std::less specializations. + */ +inline +bool before(const std::type_info* lhs, const std::type_info* rhs) +{ +#if LL_LINUX && defined(__GNUC__) && ((__GNUC__ < 4) || (__GNUC__ == 4 && __GNUC_MINOR__ < 4)) + // If we're building on Linux with gcc, and it's either gcc 3.x or + // 4.{0,1,2,3}, then we have to use a workaround. Note that we use gcc on + // Mac too, and some people build with gcc on Windows (cygwin or mingw). + // On Linux, different load modules may produce different type_info* + // pointers for the same type. Have to compare name strings to get good + // results. + return strcmp(lhs->name(), rhs->name()) < 0; +#else // not Linux, or gcc 4.4+ + // Just use before(), as we normally would + return lhs->before(*rhs); +#endif +} + +/** + * Specialize std::less<std::type_info*> to use std::type_info::before(). + * See MAINT-1175. It is NEVER a good idea to directly compare std::type_info* + * because, on Linux, you might get different std::type_info* pointers for the + * same type (from different load modules)! + */ +namespace std +{ + template <> + struct less<const std::type_info*>: + public std::binary_function<const std::type_info*, const std::type_info*, bool> + { + bool operator()(const std::type_info* lhs, const std::type_info* rhs) const + { + return before(lhs, rhs); + } + }; + + template <> + struct less<std::type_info*>: + public std::binary_function<std::type_info*, std::type_info*, bool> + { + bool operator()(std::type_info* lhs, std::type_info* rhs) const + { + return before(lhs, rhs); + } + }; +} // std + + +/** + * Implementation for ll_template_cast() (q.v.). + * + * Default implementation: trying to cast two completely unrelated types + * returns 0. Typically you'd specify T and U as pointer types, but in fact T + * can be any type that can be initialized with 0. + */ +template <typename T, typename U> +struct ll_template_cast_impl +{ + T operator()(U) + { + return 0; + } +}; + +/** + * ll_template_cast<T>(some_value) is for use in a template function when + * some_value might be of arbitrary type, but you want to recognize type T + * specially. + * + * It's designed for use with pointer types. Example: + * @code + * struct SpecialClass + * { + * void someMethod(const std::string&) const; + * }; + * + * template <class REALCLASS> + * void somefunc(const REALCLASS& instance) + * { + * const SpecialClass* ptr = ll_template_cast<const SpecialClass*>(&instance); + * if (ptr) + * { + * ptr->someMethod("Call method only available on SpecialClass"); + * } + * } + * @endcode + * + * Why is this better than dynamic_cast<>? Because unless OtherClass is + * polymorphic, the following won't even compile (gcc 4.0.1): + * @code + * OtherClass other; + * SpecialClass* ptr = dynamic_cast<SpecialClass*>(&other); + * @endcode + * to say nothing of this: + * @code + * void function(int); + * SpecialClass* ptr = dynamic_cast<SpecialClass*>(&function); + * @endcode + * ll_template_cast handles these kinds of cases by returning 0. + */ +template <typename T, typename U> +T ll_template_cast(U value) +{ + return ll_template_cast_impl<T, U>()(value); +} + +/** + * Implementation for ll_template_cast() (q.v.). + * + * Implementation for identical types: return same value. + */ +template <typename T> +struct ll_template_cast_impl<T, T> +{ + T operator()(T value) + { + return value; + } +}; + +/** + * LL_TEMPLATE_CONVERTIBLE(dest, source) asserts that, for a value @c s of + * type @c source, <tt>ll_template_cast<dest>(s)</tt> will return @c s -- + * presuming that @c source can be converted to @c dest by the normal rules of + * C++. + * + * By default, <tt>ll_template_cast<dest>(s)</tt> will return 0 unless @c s's + * type is literally identical to @c dest. (This is because of the + * straightforward application of template specialization rules.) That can + * lead to surprising results, e.g.: + * + * @code + * Foo myFoo; + * const Foo* fooptr = ll_template_cast<const Foo*>(&myFoo); + * @endcode + * + * Here @c fooptr will be 0 because <tt>&myFoo</tt> is of type <tt>Foo*</tt> + * -- @em not <tt>const Foo*</tt>. (Declaring <tt>const Foo myFoo;</tt> would + * force the compiler to do the right thing.) + * + * More disappointingly: + * @code + * struct Base {}; + * struct Subclass: public Base {}; + * Subclass object; + * Base* ptr = ll_template_cast<Base*>(&object); + * @endcode + * + * Here @c ptr will be 0 because <tt>&object</tt> is of type + * <tt>Subclass*</tt> rather than <tt>Base*</tt>. We @em want this cast to + * succeed, but without our help ll_template_cast can't recognize it. + * + * The following would suffice: + * @code + * LL_TEMPLATE_CONVERTIBLE(Base*, Subclass*); + * ... + * Base* ptr = ll_template_cast<Base*>(&object); + * @endcode + * + * However, as noted earlier, this is easily fooled: + * @code + * const Base* ptr = ll_template_cast<const Base*>(&object); + * @endcode + * would still produce 0 because we haven't yet seen: + * @code + * LL_TEMPLATE_CONVERTIBLE(const Base*, Subclass*); + * @endcode + * + * @TODO + * This macro should use Boost type_traits facilities for stripping and + * re-adding @c const and @c volatile qualifiers so that invoking + * LL_TEMPLATE_CONVERTIBLE(dest, source) will automatically generate all + * permitted permutations. It's really not fair to the coder to require + * separate: + * @code + * LL_TEMPLATE_CONVERTIBLE(Base*, Subclass*); + * LL_TEMPLATE_CONVERTIBLE(const Base*, Subclass*); + * LL_TEMPLATE_CONVERTIBLE(const Base*, const Subclass*); + * @endcode + * + * (Naturally we omit <tt>LL_TEMPLATE_CONVERTIBLE(Base*, const Subclass*)</tt> + * because that's not permitted by normal C++ assignment anyway.) + */ +#define LL_TEMPLATE_CONVERTIBLE(DEST, SOURCE) \ +template <> \ +struct ll_template_cast_impl<DEST, SOURCE> \ +{ \ + DEST operator()(SOURCE wrapper) \ + { \ + return wrapper; \ + } \ +} + + #endif // LL_LLSTL_H |