wifi: Use volt_u weak alias

examples/wireless/wifi-sleep.cc

@@ -103,7 +103,7 @@ main(int argc, char* argv[])
     uint32_t packetSize{1000}; // bytes
     Time duration{"10s"};
     double initialEnergy{7.5}; // joule
-    double voltage{3.0};       // volts
+    volt_u voltage{3.0};
     dBm_u txPowerStart{0.0};
     dBm_u txPowerEnd{15.0};
     uint32_t nTxPowerLevels{16};

src/wifi/model/wifi-tx-current-model.cc

@@ -54,7 +54,7 @@ LinearWifiTxCurrentModel::GetTypeId()
                           "The supply voltage (in Volts).",
                           DoubleValue(3.0),
                           MakeDoubleAccessor(&LinearWifiTxCurrentModel::m_voltage),
-                          MakeDoubleChecker<double>())
+                          MakeDoubleChecker<volt_u>())
             .AddAttribute("IdleCurrent",
                           "The current in the IDLE state (in Ampere).",
                           DoubleValue(0.273333),

src/wifi/model/wifi-tx-current-model.h

@@ -88,7 +88,7 @@ class LinearWifiTxCurrentModel : public WifiTxCurrentModel
 
   private:
     double m_eta;           ///< ETA
-    double m_voltage;       ///< voltage in Volts
+    volt_u m_voltage;       ///< voltage
     ampere_u m_idleCurrent; ///< idle current
 };