  One of the central problems in the study of quantum resource theories is to
provide a given resource with an operational meaning, characterizing physical
tasks in which the resource can give an explicit advantage over all
resourceless states. We show that this can always be accomplished for all
convex resource theories. We establish in particular that any resource state
enables an advantage in a channel discrimination task, allowing for a strictly
greater success probability than any state without the given resource.
Furthermore, we find that the generalized robustness measure serves as an exact
quantifier for the maximal advantage enabled by the given resource state in a
class of subchannel discrimination problems, providing a universal operational
interpretation to this fundamental resource quantifier. We also consider a
wider range of subchannel discrimination tasks and show that the generalized
robustness still serves as the operational advantage quantifier for several
well-known theories such as entanglement, coherence, and magic.
