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Использование =============","type":"unstyled","key":"dc6cj"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":12,"offset":0,"style":"ITALIC"}],"text":"int main() {","type":"unstyled","key":"fp7ga"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":43,"offset":0,"style":"ITALIC"}],"text":"std::vector memoryBuffer; // В памяти","type":"unstyled","key":"22sna"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":55,"offset":0,"style":"ITALIC"}],"text":"std::FILE* file = nullptr; // На диске (имитация)","type":"unstyled","key":"bpj06"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":62,"offset":0,"style":"ITALIC"}],"text":"const char* url = \"http://example.com/data\"; // Сетевой адрес","type":"unstyled","key":"qaa"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":41,"offset":0,"style":"ITALIC"}],"text":"loadData(memoryBuffer); // FromMemoryTag","type":"unstyled","key":"2ni38"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":39,"offset":0,"style":"ITALIC"}],"text":"loadData(file); // FromDiskTag","type":"unstyled","key":"3k830"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":42,"offset":0,"style":"ITALIC"}],"text":"loadData(url); // FromNetworkTag","type":"unstyled","key":"6ajkh"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":9,"offset":0,"style":"ITALIC"}],"text":"return 0;","type":"unstyled","key":"agk56"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":1,"offset":0,"style":"ITALIC"}],"text":"}","type":"unstyled","key":"85ies"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Что здесь происходит?","type":"unstyled","key":"cnl8p"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":72,"offset":43,"style":"ITALIC"}],"text":"1. Компилятор смотрит на тип источника : std::vector → тег FromMemoryTag , std::FILE* → тег FromDiskTag","type":"unstyled","key":"ee10r"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":13,"offset":36,"style":"ITALIC"}],"text":"2. Создает временный объект-тег : FromDiskTag()","type":"unstyled","key":"dorfc"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"3. Выбирает перегрузку по этому типу","type":"unstyled","key":"6ubqq"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"4. Генерирует код только для выбранной реализации","type":"unstyled","key":"2qvjn"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":28,"offset":9,"style":"ITALIC"}],"text":"Никаких if (sourceType == \"network\") в рантайме. Весь выбор сделан компилятором.","type":"unstyled","key":"in4p"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Когда использовать Tag Dispatching?","type":"unstyled","key":"fr9mf"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"Идеальные кандидаты:","type":"unstyled","key":"fn6jk"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":48,"offset":3,"style":"ITALIC"}],"text":"- Обобщенные алгоритмы , работающие с итераторами разных категорий","type":"unstyled","key":"2mesg"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"- Фабрики , создающие объекты по типу входных данных","type":"unstyled","key":"it7f"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":12,"offset":3,"style":"ITALIC"}],"text":"- Сериализация с разными форматами (бинарный, текстовый, JSON)","type":"unstyled","key":"6kmu"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"- Оптимизации для специфических типов (например, POD-типы можно копировать memcpy )","type":"unstyled","key":"8d7go"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":15,"offset":0,"style":"BOLD"}],"text":"Когда не нужно:","type":"unstyled","key":"aklvn"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"- Если выбор зависит от значения , а не от типа (используйте if constexpr или обычные условия)","type":"unstyled","key":"a2usr"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"- В простых случаях, где перегрузка по основным типам и так работает","type":"unstyled","key":"gak6"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":5,"offset":8,"style":"ITALIC"}],"text":"- Когда нужно менять поведение в рантайме (нужен полиморфизм)","type":"unstyled","key":"c8pn1"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":15,"offset":0,"style":"BOLD"}],"text":"Tag Dispatching — это элегантный пример того, как использовать мощь системы типов C++ для написания эффективного и самодокументируемого кода. Эта идиома превращает выбор алгоритма из рантайм-проверки в стройную систему перегрузок, где компилятор выступает идеальным диспетчером.","type":"unstyled","key":"6s3ge"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[{"length":6,"offset":52,"style":"ITALIC"},{"length":21,"offset":70,"style":"ITALIC"}],"text":"Следующий раз, когда будете писать функцию, которая должна вести себя по-разному для разных типов, вспомните о тегах. Возможно, это именно то, что вам нужно! ","type":"unstyled","key":"6h1mm"},{"data":{},"depth":0,"entityRanges":[],"inlineStyleRanges":[],"text":"","type":"marker","key":"aKFJUKmhmH4JfYJ44XXt"}],"entityMap":{}},"mentions":[]}