{"id":1621,"date":"2013-06-07T20:19:36","date_gmt":"2013-06-08T01:19:36","guid":{"rendered":"http:\/\/bitpost.com\/news\/?p=1621"},"modified":"2013-11-06T15:48:36","modified_gmt":"2013-11-06T20:48:36","slug":"quick-c11-containers-summary","status":"publish","type":"post","link":"https:\/\/bitpost.com\/news\/2013\/quick-c11-containers-summary\/","title":{"rendered":"Quick C++11 containers summary"},"content":{"rendered":"\n\n\n\n\n\n\n\n
c++11 containers\n<\/th>\n<\/tr>\n
sorted_vector<\/a> <\/td>\n use when doing lots of unsorted insertions and maintaining constant sort would be expensive\n<\/td>\n<\/tr>\n
map <\/td>\n sorted binary search tree; always sorted by key; you can walk through in sorted order\n<\/td>\n<\/tr>\n
multimap <\/td>\n same as map but allows dupe keys; need for this should be pretty rare\n<\/td>\n<\/tr>\n
unordered_map <\/td>\n hashmap; always sorted by key; additional bucket required for hash collisions; no defined order when walking through\n<\/td>\n<\/tr>\n
unordered_multimap <\/td>\n same as map but allows dupe keys; dupes are obviously in the same bucket, and you can walk just the dupes if needed\n<\/td>\n<\/tr>\n
set
multiset
unordered_set
unordered_multiset <\/td>\n		sets are just like maps, except the key is embedded in the object, great idea
\nbut… they are ruined by the constraint that contained items must be const
\nbut… then redeemed by mutable
\nYou can use mutable on the variable that are not part of the key to remove the const!
\nThis changes the constness of the object from binary (completely const) to logical (constness is defined by the developer)
\nso… set is an excellent way to achieve both encapsulation and logical const<\/p>\n

Final note: using object pointers is the ultimate solution.
\nThe entire object can be dereferenced and accessed then without const issues.
\nTwo requirements: you must make sure yourself that you do not change the key values;
\nyou must create sort functors that dereference the pointers to sort using object contents if needed
\n(the default sorting will be by pointer address).
\nThe arguably biggest advantage, as a result, is that you can create multiple sets
\nto reference the same group of objects with different sort funtors to create multiple indices.
\nOH YEAH! \ud83d\ude42\n<\/td>\n<\/tr>\n<\/table>\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

c++11 containers sorted_vector use when doing lots of unsorted insertions and maintaining constant sort would be expensive map sorted binary search tree; always sorted by key; you can walk through in sorted order multimap same as map but allows dupe keys; need for this should be pretty rare unordered_map hashmap; always sorted by key; additional […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_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":[22],"tags":[190,30],"class_list":["post-1621","post","type-post","status-publish","format-standard","hentry","category-cpp","tag-c11","tag-stl"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t