Roll forward to cl/321106672

Signed-off-by: Alexey Polyudov <apolyudov@google.com>
Change-Id: Iabb20e9c7f7487268fa3ebbbeb58540092e10e0e

cpp/core_v2/options.h

@@ -7,10 +7,22 @@ namespace location {
 namespace nearby {
 namespace connections {
 
+// Generic type: allows definition of a feature T for every Medium.
+template <typename T>
+struct MediumSelector {
+  T bluetooth;
+  T web_rtc;
+  T wifi_lan;
+};
+
+// Feature On/Off switch for mediums.
+using BooleanMediumSelector = MediumSelector<bool>;
+
 // Connection Options: used for both Advertising and Discovery.
 // All fields are mutable, to make the type copy-assignable.
 struct ConnectionOptions {
   Strategy strategy;
+  BooleanMediumSelector allowed;
   bool auto_upgrade_bandwidth;
   bool enforce_topology_constraints;
   // Verify if  ConnectionOptions is in a not-initialized (Empty) state.