My Unreal project right now:
FVector
std::vector
Eigen::Vector
KDL::Vector
....
*sigh*
And people ask me why I like Lisp. A Vector is a Vector goddamit! Half my project is now just parsing the same variable to the different functions. sigh....I hate this.

I guess there's marginal semantic value in discriminating between vector and eigenvector in regards to intent. But on the whole, yeah, pick a single library if they do the same thing.

@SortOfTested I kinda need all of them. That's the sad part... T_T

Looks like you need to wrap the actually needed functionality of all that libs and do all the type-casting at the abstraction border.
Then you can always use the same vector implementation in the code wich is using the wrappers...

@Oktokolo hm. that's a good idea. But this is research code, it kinda works now and I'm running out of time, so I'll put that on my future features list ^^

@hasu
Well, research code normally has the following life cycle:
It gets made. Then it gets improved until it is fit for its purpose (normally a paper or degree). Then it is abandoned and never gets touched again.

Maybe, you actually plan on maintaining it later. But the myriads of rotten research projects out in the wild are overwhelming evidence for such a future being highly unlikely.

So skip the todo list. Get it good enough, turn it into publication score or a degree and move on to the next project to repeat the cycle...

@Oktokolo it's part of my degree. but we kinda want to make it into a plugin later. At least, that's the goal. So hopefully, it will see some love later on and I will end up maintaining it. Hopefully