std::map implementation guide Values as Expected in C++17 with Custom Comparator
I'm working on a project and hit a roadblock. I've been banging my head against this for hours. I'm experiencing an scenario where my `std::map` is not updating values as expected when using a custom comparator. I have a custom struct as the key, and I want to store an integer value associated with each key. However, when I try to update the value associated with an existing key, it does not seem to change, and the map retains the old value. Here's a minimal example of what I'm doing: ```cpp #include <iostream> #include <map> #include <string> struct Key { std::string name; int id; bool operator<(const Key& other) const { return id < other.id; // Custom comparison based on id } }; int main() { std::map<Key, int> myMap; Key k1 = {"Item1", 1}; myMap[k1] = 10; // Attempting to update the value associated with k1 myMap[k1] = 20; // This line seems to not update the value correctly std::cout << "Value for k1: " << myMap[k1] << '\n'; // Outputs 10 instead of 20 return 0; } ``` I've confirmed that the key exists in the map, but the output is still showing the old value. I've also checked that the custom comparator is functioning correctly; the keys appear to be compared properly when inserted. Why am I seeing this behavior? Is there something wrong with how I defined the comparator or how I'm using the `std::map`? I've tried using `myMap.at(k1)` as well, but it gives the same result. Any help would be appreciated! For context: I'm using Cpp on Windows. My team is using Cpp for this web app. Any ideas how to fix this? My team is using Cpp for this microservice. Thanks, I really appreciate it!