{"id":1387,"date":"2012-10-28T00:00:50","date_gmt":"2012-10-27T22:00:50","guid":{"rendered":"http:\/\/mariusbancila.ro\/blog\/?p=1387"},"modified":"2012-11-23T12:56:06","modified_gmt":"2012-11-23T10:56:06","slug":"cpplinq-range-generators-and-conversion-operators","status":"publish","type":"post","link":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/","title":{"rendered":"cpplinq: range generators and conversion operators"},"content":{"rendered":"<p>In my <a href=\"http:\/\/mariusbancila.ro\/blog\/2012\/10\/24\/cpplinq-an-introduction\/\">previous post<\/a> I introduced <a href=\"http:\/\/cpplinq.codeplex.com\/\">cpplinq<\/a>, a C++ template library that provides .NET-like query operators for sequences of objects in C++11. In this second installment I will discuss about two things: range generators and range conversion operators. These two sets of operators are ubiquitous in queries.<\/p>\n<h3>Range generators<\/h3>\n<p>A range generator builds an object that represents the range on which query operators are applied. The library provides several such generators:<\/p>\n<ul>\n<li><strong>from_iterators<\/strong>: constructs a range from a pair of iterators<\/li>\n<li><strong>from<\/strong>: constructs a range from an STL-like container that provides begin() and end() methods (representing the first and past-the-end elements). This is basically a wrapper on from_iterators operator.\n<pre class=\"cpp\" name=\"code\">\r\nstd::vector&lt;int&gt; numbers;\r\nnumbers.push_back(1);\r\nnumbers.push_back(2);\r\nnumbers.push_back(3);\r\nnumbers.push_back(4);\r\nnumbers.push_back(5);\r\n\r\nauto result = from(numbers);\r\nresult >> for_each([](int i) {std::cout << i << std::endl;});\r\n<\/pre>\n<p>This is similar to:<\/p>\n<pre class=\"cpp\" name=\"code\">\r\nauto result = from_iterators(numbers.begin(), numbers.end());\r\n<\/pre>\n<\/li>\n<li><strong>from_array<\/strong>: constructs a range from an array.\n<pre class=\"cpp\" name=\"code\">\r\nint numbers[] = {1,2,3,4,5};\r\nauto result = from_array(numbers);\r\nresult >> for_each([](int i) {std::cout << i << std::endl;});\r\n<\/pre>\n<p>This is similar to:<\/p>\n<pre class=\"cpp\" name=\"code\">\r\nauto result = from_iterators(arrnumbers, arrnumbers + 5);\r\n<\/pre>\n<\/li>\n<\/ul>\n<p>In addition to the \"from\" operators, the library also provides several .NET like range generators:<\/p>\n<ul>\n<li><strong>range<\/strong>: generates a range of integral, consecutive numbers, starting with an initial seed and having a specified number of elements.\n<pre class=\"cpp\" name=\"code\">\r\nauto result = range(10, 90); \/\/ creates a range of numbers in the interval [10, 100)\r\n<\/pre>\n<\/li>\n<li><strong>repeat<\/strong>: generates a range by repeating a value a given number of times\n<pre class=\"cpp\" name=\"code\">\r\nauto result = repeat(\"cpplinq\", 10); \/\/ creates a range with 10 strings with the value \"cpplinq\"\r\n<\/pre>\n<\/li>\n<li><strong>empty<\/strong>: returns an empty range of a given type\n<pre class=\"cpp\" name=\"code\">\r\nauto result = empty&lt;customer&gt;(); \/\/ creates an empty range of customers\r\n<\/pre>\n<\/li>\n<\/ul>\n<h3>Range conversion operators<\/h3>\n<p>A conversion operator folds a range into a container that holds the values of the range. There are several such conversion operators that the library provides.<\/p>\n<ul>\n<li><strong>to_vector<\/strong>: creates a std::vector&lt;TValue&gt; from a range, where TValue is the type of the elements of the range.\n<pre class=\"cpp\" name=\"code\">\r\nauto result = range(1, 10) >> to_vector();\r\n\r\nstd::list&lt;int&gt; numbers;\r\nauto result = from(numbers) >> to_vector(); \/\/ transforms a list into a vector\r\n<\/pre>\n<\/li>\n<li><strong>to_list<\/strong>: creates a std::list&lt;TValue&gt; from a range, where TValue is the type of the elements of the range.\n<pre class=\"cpp\" name=\"code\">\r\nauto result = range(1, 10) >> to_list();\r\n<\/pre>\n<\/li>\n<li><strong>to_map<\/strong>: creates a std::map&lt;TKey, TValue&gt; from a range. It takes a predicate that selects the value to use as the key for each element of the range. It implements a one-to-one dictionary that maps keys to single values.\n<pre class=\"cpp\" name=\"code\">\r\n\/\/ creates a map where key is the customer ID, and the value is the customer object\r\nauto result = from_array (customers) >> to_map ([](customer const & c){return c.id;});\r\n<\/pre>\n<\/li>\n<li><strong>to_lookup<\/strong>: creates a cpplinq::lookup&lt;TKey, TElement&gt; from a sequence. It  implements a one-to-many dictionary that maps keys to sequences of values.\n<pre class=\"cpp\" name=\"code\">\r\ncustomer_address customer_addresses[] =\r\n{\r\n   customer_address (2, 4, \"Finland\"   ),\r\n   customer_address (3, 4, \"USA\"       ),\r\n   customer_address (1, 1, \"USA\"       ),\r\n};\r\n\r\nauto lookup = from_array (customer_addresses) \r\n           >> to_lookup ([] (customer_address const & ca){return ca.customer_id;}); \r\n\r\nauto countries = lookup[4] \r\n              >> select([](customer_address const & ca) {return ca.country;}) \r\n              >> to_vector();  \/\/ yields {\"Finland\", \"USA\"}\r\n<\/pre>\n<\/li>\n<\/ul>\n<p><a href=\"http:\/\/www.codeproject.com\/script\/Articles\/BlogArticleList.aspx?amid=562357\" rel=\"tag\" style=\"display:none\">CodeProject<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>In my previous post I introduced cpplinq, a C++ template library that provides .NET-like query operators for sequences of objects in C++11. In this second installment I will discuss about two things: range generators and range conversion operators. These two sets of operators are ubiquitous in queries. Range generators A range generator builds an object &#8230; <a title=\"cpplinq: range generators and conversion operators\" class=\"read-more\" href=\"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/\" aria-label=\"Read more about cpplinq: range generators and conversion operators\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_uag_custom_page_level_css":"","advgb_blocks_editor_width":"","advgb_blocks_columns_visual_guide":"","_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[7],"tags":[451,331,327,330,332,253,329,333],"class_list":["post-1387","post","type-post","status-publish","format-standard","hentry","category-c","tag-c","tag-conversion","tag-cpplinq","tag-generator","tag-operator","tag-query","tag-rang","tag-stl"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 5.0.3 - aioseo.com -->\n\t<meta name=\"description\" content=\"Discuss about range generators and range conversion operators, ubiquitous in queries with cpplinq.\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<meta name=\"author\" content=\"Marius Bancila\"\/>\n\t<meta name=\"keywords\" content=\"cpplinq,rang,generator,conversion,operator,query,stl,c++\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/\" \/>\n\t\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 5.0.3\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"Marius Bancila&#039;s Blog | About code. Mostly on C++\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"cpplinq: range generators and conversion operators\" \/>\n\t\t<meta property=\"og:description\" content=\"Discuss about range generators and range conversion operators, ubiquitous in queries with cpplinq.\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2012-10-27T22:00:50+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2012-11-23T10:56:06+00:00\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary\" \/>\n\t\t<meta name=\"twitter:title\" content=\"cpplinq: range generators and conversion operators\" \/>\n\t\t<meta name=\"twitter:description\" content=\"Discuss about range generators and range conversion operators, ubiquitous in queries with cpplinq.\" \/>\n\t\t<script type=\"application\/ld+json\" class=\"aioseo-schema\">\n\t\t\t{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/2012\\\/10\\\/28\\\/cpplinq-range-generators-and-conversion-operators\\\/#article\",\"name\":\"cpplinq: range generators and conversion operators\",\"headline\":\"cpplinq: range generators and conversion operators\",\"author\":{\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/author\\\/admin\\\/#author\"},\"publisher\":{\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/#organization\"},\"datePublished\":\"2012-10-28T00:00:50+02:00\",\"dateModified\":\"2012-11-23T12:56:06+02:00\",\"inLanguage\":\"en-US\",\"commentCount\":4,\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/2012\\\/10\\\/28\\\/cpplinq-range-generators-and-conversion-operators\\\/#webpage\"},\"isPartOf\":{\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/2012\\\/10\\\/28\\\/cpplinq-range-generators-and-conversion-operators\\\/#webpage\"},\"articleSection\":\"C++, C++, conversion, cpplinq, generator, operator, query, rang, STL\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/2012\\\/10\\\/28\\\/cpplinq-range-generators-and-conversion-operators\\\/#breadcrumblist\",\"itemListElement\":[{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/#listItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/#listItem\",\"name\":\"IT\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/#listItem\",\"position\":2,\"name\":\"IT\",\"item\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/software\\\/#listItem\",\"name\":\"Software\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/#listItem\",\"name\":\"Home\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/software\\\/#listItem\",\"position\":3,\"name\":\"Software\",\"item\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/software\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/software\\\/c\\\/#listItem\",\"name\":\"C++\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/#listItem\",\"name\":\"IT\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/software\\\/c\\\/#listItem\",\"position\":4,\"name\":\"C++\",\"item\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/software\\\/c\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/2012\\\/10\\\/28\\\/cpplinq-range-generators-and-conversion-operators\\\/#listItem\",\"name\":\"cpplinq: range generators and conversion operators\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/software\\\/#listItem\",\"name\":\"Software\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/2012\\\/10\\\/28\\\/cpplinq-range-generators-and-conversion-operators\\\/#listItem\",\"position\":5,\"name\":\"cpplinq: range generators and conversion operators\",\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/category\\\/it\\\/software\\\/c\\\/#listItem\",\"name\":\"C++\"}}]},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/#organization\",\"name\":\"Marius Bancila's Blog\",\"description\":\"About code. Mostly on C++\",\"url\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/\"},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/author\\\/admin\\\/#author\",\"url\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/author\\\/admin\\\/\",\"name\":\"Marius Bancila\",\"image\":{\"@type\":\"ImageObject\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/2012\\\/10\\\/28\\\/cpplinq-range-generators-and-conversion-operators\\\/#authorImage\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/a84dd2831d955c38355ddea55df4df260809b88f36408bc14fd4eab8f7f131c9?s=96&d=mm&r=g\",\"width\":96,\"height\":96,\"caption\":\"Marius Bancila\"}},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/2012\\\/10\\\/28\\\/cpplinq-range-generators-and-conversion-operators\\\/#webpage\",\"url\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/2012\\\/10\\\/28\\\/cpplinq-range-generators-and-conversion-operators\\\/\",\"name\":\"cpplinq: range generators and conversion operators\",\"description\":\"Discuss about range generators and range conversion operators, ubiquitous in queries with cpplinq.\",\"inLanguage\":\"en-US\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/#website\"},\"breadcrumb\":{\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/2012\\\/10\\\/28\\\/cpplinq-range-generators-and-conversion-operators\\\/#breadcrumblist\"},\"author\":{\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/author\\\/admin\\\/#author\"},\"creator\":{\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/author\\\/admin\\\/#author\"},\"datePublished\":\"2012-10-28T00:00:50+02:00\",\"dateModified\":\"2012-11-23T12:56:06+02:00\"},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/\",\"name\":\"Marius Bancila's Blog\",\"description\":\"About code. Mostly on C++\",\"inLanguage\":\"en-US\",\"publisher\":{\"@id\":\"https:\\\/\\\/mariusbancila.ro\\\/blog\\\/#organization\"}}]}\n\t\t<\/script>\n\t\t<!-- All in One SEO -->\n\n","aioseo_head_json":{"title":"cpplinq: range generators and conversion operators","description":"Discuss about range generators and range conversion operators, ubiquitous in queries with cpplinq.","canonical_url":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/","robots":"max-image-preview:large","keywords":"cpplinq,rang,generator,conversion,operator,query,stl,c++","webmasterTools":{"miscellaneous":""},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/#article","name":"cpplinq: range generators and conversion operators","headline":"cpplinq: range generators and conversion operators","author":{"@id":"https:\/\/mariusbancila.ro\/blog\/author\/admin\/#author"},"publisher":{"@id":"https:\/\/mariusbancila.ro\/blog\/#organization"},"datePublished":"2012-10-28T00:00:50+02:00","dateModified":"2012-11-23T12:56:06+02:00","inLanguage":"en-US","commentCount":4,"mainEntityOfPage":{"@id":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/#webpage"},"isPartOf":{"@id":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/#webpage"},"articleSection":"C++, C++, conversion, cpplinq, generator, operator, query, rang, STL"},{"@type":"BreadcrumbList","@id":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/#breadcrumblist","itemListElement":[{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/#listItem","position":1,"name":"Home","item":"https:\/\/mariusbancila.ro\/blog\/","nextItem":{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/category\/it\/#listItem","name":"IT"}},{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/category\/it\/#listItem","position":2,"name":"IT","item":"https:\/\/mariusbancila.ro\/blog\/category\/it\/","nextItem":{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/#listItem","name":"Software"},"previousItem":{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/#listItem","name":"Home"}},{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/#listItem","position":3,"name":"Software","item":"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/","nextItem":{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/#listItem","name":"C++"},"previousItem":{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/category\/it\/#listItem","name":"IT"}},{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/#listItem","position":4,"name":"C++","item":"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/","nextItem":{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/#listItem","name":"cpplinq: range generators and conversion operators"},"previousItem":{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/#listItem","name":"Software"}},{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/#listItem","position":5,"name":"cpplinq: range generators and conversion operators","previousItem":{"@type":"ListItem","@id":"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/#listItem","name":"C++"}}]},{"@type":"Organization","@id":"https:\/\/mariusbancila.ro\/blog\/#organization","name":"Marius Bancila's Blog","description":"About code. Mostly on C++","url":"https:\/\/mariusbancila.ro\/blog\/"},{"@type":"Person","@id":"https:\/\/mariusbancila.ro\/blog\/author\/admin\/#author","url":"https:\/\/mariusbancila.ro\/blog\/author\/admin\/","name":"Marius Bancila","image":{"@type":"ImageObject","@id":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/#authorImage","url":"https:\/\/secure.gravatar.com\/avatar\/a84dd2831d955c38355ddea55df4df260809b88f36408bc14fd4eab8f7f131c9?s=96&d=mm&r=g","width":96,"height":96,"caption":"Marius Bancila"}},{"@type":"WebPage","@id":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/#webpage","url":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/","name":"cpplinq: range generators and conversion operators","description":"Discuss about range generators and range conversion operators, ubiquitous in queries with cpplinq.","inLanguage":"en-US","isPartOf":{"@id":"https:\/\/mariusbancila.ro\/blog\/#website"},"breadcrumb":{"@id":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/#breadcrumblist"},"author":{"@id":"https:\/\/mariusbancila.ro\/blog\/author\/admin\/#author"},"creator":{"@id":"https:\/\/mariusbancila.ro\/blog\/author\/admin\/#author"},"datePublished":"2012-10-28T00:00:50+02:00","dateModified":"2012-11-23T12:56:06+02:00"},{"@type":"WebSite","@id":"https:\/\/mariusbancila.ro\/blog\/#website","url":"https:\/\/mariusbancila.ro\/blog\/","name":"Marius Bancila's Blog","description":"About code. Mostly on C++","inLanguage":"en-US","publisher":{"@id":"https:\/\/mariusbancila.ro\/blog\/#organization"}}]},"og:locale":"en_US","og:site_name":"Marius Bancila's Blog | About code. Mostly on C++","og:type":"article","og:title":"cpplinq: range generators and conversion operators","og:description":"Discuss about range generators and range conversion operators, ubiquitous in queries with cpplinq.","og:url":"https:\/\/mariusbancila.ro\/blog\/2012\/10\/28\/cpplinq-range-generators-and-conversion-operators\/","article:published_time":"2012-10-27T22:00:50+00:00","article:modified_time":"2012-11-23T10:56:06+00:00","twitter:card":"summary","twitter:title":"cpplinq: range generators and conversion operators","twitter:description":"Discuss about range generators and range conversion operators, ubiquitous in queries with cpplinq."},"aioseo_meta_data":{"post_id":"1387","title":"cpplinq: range generators and conversion operators","description":"Discuss about range generators and range conversion operators, ubiquitous in queries with cpplinq.","keywords":[{"label":"cpplinq","value":"cpplinq"},{"label":"rang","value":"rang"},{"label":"generator","value":"generator"},{"label":"conversion","value":"conversion"},{"label":"operator","value":"operator"},{"label":"query","value":"query"},{"label":"STL","value":"STL"},{"label":"C++","value":"C++"}],"keyphrases":null,"primary_term":null,"canonical_url":null,"og_title":null,"og_description":null,"og_object_type":"default","og_image_type":"default","og_image_url":null,"og_image_width":null,"og_image_height":null,"og_image_custom_url":null,"og_image_custom_fields":null,"og_video":null,"og_custom_url":null,"og_article_section":null,"og_article_tags":null,"twitter_use_og":false,"twitter_card":"default","twitter_image_type":"default","twitter_image_url":null,"twitter_image_custom_url":null,"twitter_image_custom_fields":null,"twitter_title":null,"twitter_description":null,"schema":{"blockGraphs":[],"customGraphs":[],"default":{"data":{"Article":[],"Course":[],"Dataset":[],"FAQPage":[],"Movie":[],"Person":[],"Product":[],"ProductReview":[],"Car":[],"Recipe":[],"Service":[],"SoftwareApplication":[],"WebPage":[]},"graphName":"","isEnabled":true},"graphs":[]},"schema_type":null,"schema_type_options":null,"pillar_content":false,"robots_default":true,"robots_noindex":false,"robots_noarchive":false,"robots_nosnippet":false,"robots_nofollow":false,"robots_noimageindex":false,"robots_noodp":false,"robots_notranslate":false,"robots_max_snippet":null,"robots_max_videopreview":null,"robots_max_imagepreview":"large","priority":null,"frequency":null,"location":null,"local_seo":null,"breadcrumb_settings":null,"limit_modified_date":false,"ai":null,"created":"2021-03-18 21:12:20","updated":"2025-12-12 07:38:19","seo_analyzer_scan_date":null,"focus_keyword":null,"additional_keywords":null,"truseo_locale":null},"author_meta":{"display_name":"Marius Bancila","author_link":"https:\/\/mariusbancila.ro\/blog\/author\/admin\/"},"featured_img":null,"jetpack_publicize_connections":[],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false},"uagb_author_info":{"display_name":"Marius Bancila","author_link":"https:\/\/mariusbancila.ro\/blog\/author\/admin\/"},"uagb_comment_info":4,"uagb_excerpt":"In my previous post I introduced cpplinq, a C++ template library that provides .NET-like query operators for sequences of objects in C++11. In this second installment I will discuss about two things: range generators and range conversion operators. These two sets of operators are ubiquitous in queries. Range generators A range generator builds an object&hellip;","coauthors":[],"tax_additional":{"categories":{"linked":["<a href=\"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/\" class=\"advgb-post-tax-term\">C++<\/a>"],"unlinked":["<span class=\"advgb-post-tax-term\">C++<\/span>"]},"tags":{"linked":["<a href=\"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/\" class=\"advgb-post-tax-term\">C++<\/a>","<a href=\"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/\" class=\"advgb-post-tax-term\">conversion<\/a>","<a href=\"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/\" class=\"advgb-post-tax-term\">cpplinq<\/a>","<a href=\"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/\" class=\"advgb-post-tax-term\">generator<\/a>","<a href=\"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/\" class=\"advgb-post-tax-term\">operator<\/a>","<a href=\"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/\" class=\"advgb-post-tax-term\">query<\/a>","<a href=\"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/\" class=\"advgb-post-tax-term\">rang<\/a>","<a href=\"https:\/\/mariusbancila.ro\/blog\/category\/it\/software\/c\/\" class=\"advgb-post-tax-term\">STL<\/a>"],"unlinked":["<span class=\"advgb-post-tax-term\">C++<\/span>","<span class=\"advgb-post-tax-term\">conversion<\/span>","<span class=\"advgb-post-tax-term\">cpplinq<\/span>","<span class=\"advgb-post-tax-term\">generator<\/span>","<span class=\"advgb-post-tax-term\">operator<\/span>","<span class=\"advgb-post-tax-term\">query<\/span>","<span class=\"advgb-post-tax-term\">rang<\/span>","<span class=\"advgb-post-tax-term\">STL<\/span>"]}},"comment_count":"4","relative_dates":{"created":"Posted 14 years ago","modified":"Updated 14 years ago"},"absolute_dates":{"created":"Posted on October 28, 2012","modified":"Updated on November 23, 2012"},"absolute_dates_time":{"created":"Posted on October 28, 2012 12:00 am","modified":"Updated on November 23, 2012 12:56 pm"},"featured_img_caption":"","series_order":"","jetpack_shortlink":"https:\/\/wp.me\/pYNdv-mn","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/mariusbancila.ro\/blog\/wp-json\/wp\/v2\/posts\/1387","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mariusbancila.ro\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mariusbancila.ro\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mariusbancila.ro\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mariusbancila.ro\/blog\/wp-json\/wp\/v2\/comments?post=1387"}],"version-history":[{"count":15,"href":"https:\/\/mariusbancila.ro\/blog\/wp-json\/wp\/v2\/posts\/1387\/revisions"}],"predecessor-version":[{"id":1408,"href":"https:\/\/mariusbancila.ro\/blog\/wp-json\/wp\/v2\/posts\/1387\/revisions\/1408"}],"wp:attachment":[{"href":"https:\/\/mariusbancila.ro\/blog\/wp-json\/wp\/v2\/media?parent=1387"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mariusbancila.ro\/blog\/wp-json\/wp\/v2\/categories?post=1387"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mariusbancila.ro\/blog\/wp-json\/wp\/v2\/tags?post=1387"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}