memory errors with std::map

[itsmeandnobodyelse]

First this is a simplified example, and actually a really need to store pointers and not objects.

A pointer will have same size as a double with newer compilers. Why should there be a need to store a pointer rather than an object (a copy)?

If you want to store the same variable into multiple containers and therefore have to use pointers, in my opinion you make a design error where I know not one single case where this really must be done that way. When the pointer must be deleted you need to update all the containers where the pointer is stored anyway. So you could do an update in multiple containers as well if storing a copy of the same object into multiple containers (if that really was necessary at all where I have serious doubts about.

On the contrary, storing pointers to containers nearly always give problems like the one you did encounter here and storing them to multiple containers always will lead to highly error-prone software which only can be maintained badly. I can see from your response that you already know that and the sooner you would make a new design the sooner you would solve the problems that arise only because of this.