std::unordered_map

Think of this container as an unsorted version of std::map. It associates keys with values but without imposing any order. Instead, it banks on hashing for swift operations.

Purpose and suitability

std::unordered_map is a hash table-based key-value container in the STL. Its core strengths are as follows:

• Fast average-case key-based access, insertion, and removal
• Ability to maintain a key-value association

This container is the go-to in the following circumstances:

• When insertions, deletions, and lookups must be swift on average
• When the order of elements isn’t a concern

Ideal use cases

The following are some of the ideal use cases for std::unordered_map:

• Fast associative lookups: When you need quick access to values based on unique keys, std::unordered_map provides average constant-time complexity for search, insert, and delete operations
• Cache systems: When implementing cache mechanisms where the...