  To describe certain facets of non-classicality, it is necessary to quantify
properties of operations instead of states. This is the case if one wants to
quantify how well an operation detects non-classicality, which is a necessary
prerequisite for its use in quantum technologies. To do so rigorously, we build
resource theories on the level of operations, exploiting the concept of
resource destroying maps. We discuss the two basic ingredients of these
resource theories, the free operations and the free super-operations, which are
sequential and parallel concatenations with free operations. This leads to
defining properties of functionals that are well suited to quantify the
resources of operations. We introduce these concepts at the example of
coherence. In particular, we present two measures quantifying the ability of an
operation to detect, i.e. to use, coherence, one of them with an operational
interpretation, and provide methods to evaluate them.
