What does std::vector::reserve do in C++?

Can you explain what std::vector::reserve does in C++?

Sure! std::vector::reserve is a member function that requests to increase the capacity of a vector to at least the specified size.

Why would I want to use reserve instead of just pushing back elements?

Using reserve can improve performance by minimizing reallocations. It allocates memory in advance, reducing the need for multiple memory allocations as you add elements.

Does reserve change the size of the vector?

No, reserve only changes the capacity. The size of the vector remains the same until you add elements.

Can you give an example of how to use reserve?

Certainly! Here's a simple example:

std::vector<int> vec;
vec.reserve(10); // reserves space for 10 integers