Emplace Enhancements for Maps and Unordered Maps

Here we'll work with some of the new methods available in maps.

We'll cover the following

​With C++17 you get two new methods for maps and unordered maps:

  • try_emplace() - if the object already exists, then it does nothing; otherwise,​ it behaves like emplace().

  • emplace() might move from the input parameter when the key is in the map, that’s why it’s best to use find() before such emplacement.

  • insert_or_assign() - gives more information than operator[] - as it returns if the element was newly inserted or updated and also works with types that have no default constructor.

try_emplace Method

Here’s an example:

Get hands-on with 1400+ tech skills courses.