What are the uses of std::variant in C++11?

What are the uses of std::variant in C++11?

std::variant is a type-safe union that can hold one of several types. It's useful for scenarios where a variable can take on multiple types.

Can you give me an example of how to use std::variant?

Sure! Here's a simple example:

#include <variant>
#include <iostream>

std::variant<int, std::string> myVariant;

myVariant = 42; // holds an int
std::cout << std::get<int>(myVariant) << std::endl;

myVariant = "Hello, World!"; // now holds a string
std::cout << std::get<std::string>(myVariant) << std::endl;

What are the advantages of using std::variant over traditional unions?

The main advantages are type safety and better error handling. With std::variant, you can use std::get to safely retrieve the value, and it throws an exception if the type doesn't match.

Are there any performance considerations I should be aware of?

Yes, std::variant may have some overhead compared to traditional unions due to type safety features, but it often leads to safer and more maintainable code.