How do I pattern match (std::visit) std::variant in C++?

In C++, you can use `std::visit` to perform pattern matching on `std::variant`. The `std::variant` is a type-safe union that can hold one of several types. `std::visit` allows you to apply a visitor function to the currently held value of the variant. This can simplify code significantly when dealing with different types contained in a variant.

Here's a brief example demonstrating how to use `std::visit` with `std::variant`:


        #include <iostream>
        #include <variant>
        #include <string>

        // Define a variant that can hold an int, a double, or a string
        using MyVariant = std::variant<int, double, std::string>;

        // Visitor function to handle different types
        struct VarVisitor {
            void operator()(int value) const {
                std::cout << "Integer: " << value << std::endl;
            }

            void operator()(double value) const {
                std::cout << "Double: " << value << std::endl;
            }

            void operator()(const std::string &value) const {
                std::cout << "String: " << value << std::endl;
            }
        };

        int main() {
            MyVariant v1 = 10;
            MyVariant v2 = 3.14;
            MyVariant v3 = "Hello, Variant!";

            // Use std::visit to apply the visitor
            std::visit(VarVisitor{}, v1);
            std::visit(VarVisitor{}, v2);
            std::visit(VarVisitor{}, v3);

            return 0;
        }

C++ std::variant std::visit pattern matching variant type-safe union

How do I pattern match (std::visit) std::variant in C++?

Popular Topics

Recent Languages

How do I pattern match (std::visit) std::variant in C++?

Related Questions

Popular Topics

Recent Languages