Find and remove unique_ptr from a map

Question

I have a map<std::string, std::unique_ptr<Cls>> my_map . I would like to move out some value from this map, to have the following:

std::unique_ptr<Cls> cls = my_map.get_and_erase("some str");

erase doesn't return a value unfortunately. What is my best approach here?

Answer 1

Since C++17 you have std::map::extract :

// if the key exists in the map, it'll be deleted after this:
auto cls_node =  my_map.extract("some str");

if(not cls_node.empty()) // cls_node.value() gives access to the value

Answer 2

You can use the following algorithm:

• Use find to get an iterator to the element.
• Move from the element.
• Erase using the iterator.