How do I use emplace vs push with std::multimap?

In C++, both `emplace` and `push` (or `insert`) can be used with `std::multimap` to add elements, but they function differently.

The `emplace` member function constructs an element in-place, using the given arguments to initialize the element directly in the container. This can be more efficient as it avoids unnecessary copies or moves.

On the other hand, `push` (or `insert`) requires creating a temporary object before inserting it into the multimap.

Example of Using emplace and insert with std::multimap

#include <iostream> #include <map> int main() { std::multimap mmap; // Using insert (push) mmap.insert(std::make_pair(1, "One")); mmap.insert(std::make_pair(2, "Two")); // Using emplace mmap.emplace(3, "Three"); mmap.emplace(4, "Four"); // Displaying the contents of the multimap for (const auto& pair : mmap) { std::cout << pair.first << ": " << pair.second << std::endl; } return 0; }

C++ std::multimap emplace insert push example data structures

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