c++ - how to update a leaky integrate and fire neuron -

i'm trying implement leaky integrate , fire neuron in c++, can't figure out , efficient way update neuron's voltage when new current arrives.

i using code write now, new field , don't think optimal solution. right way update neuron?

void lif_neuron::update(double current, size_t time){     //update current     //formula: (v_current - v_reset)*(1-exp((t_last_fired - t_now)/rc)) + r*i     mcurrentvolt += -1*(mcurrentvolt-mresetvolt)*(1-exp((mlasttimefired-time)/mrc)) + mr*current;      //all leakage since last activation substracted, give substracted in earlier updates     mcurrentvolt += (mcurrentvolt-mresetvolt)*(1-exp((mlasttimefired-mlasttimeupdated)/mrc));      if(mcurrentvolt >= mthreshold){         mfires = true;         mlasttimefired = time;     }else{         mfires = false;     }      mlasttimeupdated = time; } 

mrc , mr constants of neuron.