What are the key features of std::vector in C++?

What are the key features of std::vector in C++?

The std::vector in C++ is a dynamic array that can resize itself automatically. Key features include:

1. Dynamic sizing: It can grow and shrink as needed.
2. Random access: Elements can be accessed in constant time.
3. Memory management: It handles memory allocation and deallocation automatically.
4. STL compatibility: It works seamlessly with the Standard Template Library.

How does std::vector manage memory?

std::vector manages memory by allocating a contiguous block of memory for its elements. When the vector grows beyond its current capacity, it allocates a new larger block, copies the existing elements to the new block, and then deallocates the old block. This ensures efficient memory usage and minimizes fragmentation.

Can I store different data types in a std::vector?

No, std::vector is designed to store elements of a single data type. However, you can use std::variant or std::any to store different types in a single vector, but this requires additional handling.

What are the performance implications of using std::vector?

Using std::vector generally offers good performance due to its contiguous memory allocation, which enhances cache locality. However, frequent resizing can lead to performance overhead. It's best to reserve space in advance if the size is known to avoid multiple reallocations.