Menu
When defining a std::map, does it make sense to make the key type const?
753
C++ Software Engineering Multi-map in C++ is an associative container like map. It internally store elements in key value pair. But unlike map which store only unique keys, multimap can have duplicate keys.
Yes -- when you insert an item into an std::map, you pass it by value, so what it contains is a copy of what you passed.
This is why every key has to be unique, and no two keys can be the same(but the values associated to keys can be the same). Maps in C++ store the key-value pairs in sorted order by default so that the search for any key-value pair can be very quick.
All the elements of the set are unique. A map data structure in C++ is a structure in which the list is a hash of key/value pairs, stored in ascending order of keys by default, or in descending order of keys by programmer's choice. The keys are also unique, and there can be duplicated values.
The key is already const, actually, because a key cannot change once an element was inserted in the map.
133
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
