advanced patterns with std::map and Custom Comparator in C++17: Elements Not Being Found
I'm refactoring my project and I'm experiencing unexpected behavior with a `std::map` in C++17... I created a custom comparator for the keys, which are of a user-defined type, but I'm finding that keys that I expect to be present in the map are not being found. For instance, when I try to access an element with a specific key, I get an empty result, even though the element was added previously. Here's the relevant portion of my code: ```cpp #include <iostream> #include <map> #include <string> struct CustomKey { std::string value; bool operator<(const CustomKey& other) const { return value < other.value; } }; int main() { std::map<CustomKey, int> myMap; CustomKey key1 = {"Test"}; myMap[key1] = 42; CustomKey key2 = {"Test"}; // Same value as key1 std::cout << myMap[key2] << std::endl; // Expecting to print 42 } ``` However, when I run this code, it throws an uninitialized access behavior and prints 0 instead of 42. After digging deeper, I realized that even though `key1` and `key2` have the same value, the comparison is not functioning as I expected. I verified that the `operator<` is correctly defined, but it seems like the map is treating these two keys as different due to some underlying scenario. I've tried adding print statements to check the comparisons and confirmed that the values are indeed equal. I also considered using `std::unordered_map`, but I need the ordering provided by `std::map`. What could be the reason for this behavior, and how can I ensure that my custom keys behave correctly in the map? Any insights would be appreciated! I'm working with C++ in a Docker container on Windows 11.