The paper "Applying Design by Contract" by Bertrand Meyer shows how DbC is to be used. It is sufficient to have only preconditions turned on by default in "rele

The paper "Applying Design by Contract" by Bertrand Meyer shows how DbC is to be used. It is sufficient to have only preconditions turned on by default in "release" mode, others are optional. My thumb rule is to have all preconditions/postconditions/invariants turned on only in the boundary functions (i.e. public api) of a module while the inner cohesive functions only have preconditions turned on.