[adrianratnapala]

> Your code won't be pretty,

Depends on the algorithms that use that code. Two separate arrays is not a bad way to represent a vector-of-tuples. And so if you think of everything as a vectorised operation (and if that makes sense for your use case) then the code can be clean enough.

Efficiency-wise it depends on how the locality of reference falls out. There are cases where it's more cache-efficient to store the pairs next to each other, but again for big vectorised operations you might lose nothing by using two cache-ways instead of one.