--- layout: stdlib-reference --- # diffPair ## Description Constructs a DifferentialPair value from a primal value and a differential value. ## Signature

DifferentialPair<T> diffPair<T>(
    T primal,
    T.Differential diff)
    where T : IDifferentiable;

DifferentialPair<T> diffPair<T>(T primal)
    where T : IDifferentiable;

## Generic Parameters #### T: [IDifferentiable](../interfaces/idifferentiable-01/index.html) ## Parameters #### primal : [T](diffpair-4.html#typeparam-T) #### diff : [T](diffpair-4.html#typeparam-T)\.Differential