I have a
std::map that I’m using to store values for x and y coordinates. My data is very sparse, so I don’t want to use arrays or vectors, which would result in a massive waste of memory. My data ranges from -250000 to 250000, but I’ll only have a few thousand points at the most.
Currently I’m creating a
std::string with the two coordinates (i.e.
"12x45") and using it as a key. This doesn’t seem like the best way to do it.
My other thoughts were to use an int64 and shove the two int32s into it and use it as a key.
Or to use a class with the two coordinates. What are the requirements on a class that is to be used as the key?
What is the best way to do this? I’d rather not use a map of maps.
Use std::pair<int32,int32> for the key:
std::map<std::pair<int,int>, int> myMap; myMap[std::make_pair(10,20)] = 25; std::cout << myMap[std::make_pair(10,20)] << std::endl;