Abelian::negate() took a self argument, which meant that in several cases it provoked a clone() call that wasn't strictly necessary. The negate() dataflow operator, for example, would simply clone the diff in order to negate it, which is fine for isize but less great for Vec<Diff> types.
Abelian::negate()took aselfargument, which meant that in several cases it provoked aclone()call that wasn't strictly necessary. Thenegate()dataflow operator, for example, would simply clone the diff in order to negate it, which is fine forisizebut less great forVec<Diff>types.