Hi,

Your repo is really useful, and a use it to do a Quoridor board game. When I try to use a-star, I find no documentation to know the relative limits to setWorldSize() method.

Now, I know, but it could be usefull to add this information in 'ReadMe.md' or in 'AStar.hpp'. Best fix is to add exception if 'Vec2i' when coordinates is out of range (std::out_of_range for example).

World = [ 0 ; WorldSize - 1 ]
All 'Vec2i.x' and 'Vec2i.y' have to be in [0 ; WorldSize - 1].