How flat_set is Implemented

The flat_set container is implemented as a sorted associative container, which means that its elements are sorted according to a comparison function.

However, unlike the standard set container, the flat_set stores its elements in a contiguous memory block, making it more efficient in terms of cache locality and memory usage. This is achieved by using a vector as the underlying storage for the flat_set and ensuring that the elements are always sorted in the vector.

• When an element is inserted into the flat_set, it is first located in the vector using binary search. If the element is not found, it is inserted at the appropriate position in the vector using a move operation, which preserves the sorted order of the vector.
• Similarly, when an element is removed from the flat_set, it is located in the vector using binary search and removed from the vector using a move operation.

Since the flat_set uses a vector as its underlying storage, it provides constant-time access to its elements, making it faster than the standard set container in some cases. However, the flat_set may be slower than the set container when it comes to the insertion and removal of elements, especially for large data sets.

<flat_set> is a header file that provides the implementation of the std::flat_set container class in C++, which is a sorted associative container that stores unique elements and allows for fast access, insertion, and removal of elements.

The flat_set is a container similar to the set but its elements are stored contiguously in memory. This can provide faster iteration times and better cache locality compared to std::set, especially when the container is relatively small or its elements are trivially copy-able.