How do I customize hashing and equality with std::multimap?

Customizing hashing and equality for std::multimap in C++ allows you to define how keys are compared and organized. This is essential when you need specific behavior for custom data types or want to implement complex sorting criteria.
C++, std::multimap, custom hashing, equality operator, data structures, programming tutorials
#include <iostream> #include <map> #include <string> // Custom struct to hold our data struct Person { std::string name; int age; // Overloading the comparison operator for multimap bool operator<(const Person& other) const { return name < other.name; // Compare based on name } }; int main() { // Create a multimap using our custom struct as the key std::multimap people; // Insert data into the multimap people.insert({{"Alice", 30}, "Engineer"}); people.insert({{"Bob", 25}, "Designer"}); people.insert({{"Alice", 25}, "Manager"}); // Display the contents of the multimap for (const auto& entry : people) { std::cout << entry.first.name << " (" << entry.first.age << "): " << entry.second << std::endl; } return 0; }

C++ std::multimap custom hashing equality operator data structures programming tutorials

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