Hookable Swap

[Era Scarecrow via Digitalmars-d-learn]

Making a struct type/array that visually outputs and displays 
compares/mutations of a type. While using the library sorting 
functions (which relies on std.algorithm.mutation.swap) it 
doesn't call opAssign and doesn't pass through the struct. (which 
also changes the indexes which it shouldn't).

Is there a struct override or function that forces it to be 
called for swapping or changes? Or do i simply have to detect 
changes between compares?