About templates exercises

[chavid]

• We should declare as a requirement the knowledge of object-functions.
• I wonder how the idea of "manahattan distance" mix well with the idea of complexes. Perhaps we should rather some kind of Vector2d, where the concept of distance makes more sense ?
• As said in another issue, is the "complex of complex" makes an sense in mathematics ? Not sure a Vector2d of Vector2d would be better :s

[stale]

This issue or pull request has been automatically marked as stale because it has not had recent activity. Please manually close it, if it is no longer relevant, or ask for help or support to help getting it unstuck. Let me bring this to the attention of @klieret @wdconinc @michmx for now.