Class with Volatile copy constructor and assignment operator

Accelerated Computing CUDA CUDA Programming and Performance
1

I get following warnings for coded class. Any suggestions or hints ?

heap.h: In copy constructor ‘Edge::Edge(const volatile Edge&)’:
heap.h:12: warning: object of type ‘const volatile Edge&’ will not be accessed in void context

heap.h: In member function ‘volatile Edge& Edge::operator=(volatile Edge&) volatile’:
heap.h:28: warning: object of type ‘volatile Edge&’ will not be accessed in void context

heap.h: In member function ‘bool Edge::operator<(volatile Edge&) volatile’:
heap.h:38: warning: object of type ‘volatile Edge&’ will not be accessed in void context

struct Edge {
    int vertexID;
    float edgeWeight;

   __device__ Edge() : vertexID(-1), edgeWeight(0.0) {}

    __device__ Edge(int id, float weight) {
        vertexID = id;
        edgeWeight = weight;
    }

    __device__ Edge (volatile const Edge& copy_from_me){
    	this->vertexID=copy_from_me.vertexID;
    	this->edgeWeight=copy_from_me.edgeWeight;
    }

    __device__ Edge (const  Edge& copy_from_me){
    	this->vertexID=copy_from_me.vertexID;
    	this->edgeWeight=copy_from_me.edgeWeight;
    }

    __device__  Edge& operator=(const   Edge& other) {
    	this->edgeWeight=other.edgeWeight;
    	this->vertexID=other.vertexID;
    	return *this;
    }

    __device__  volatile Edge& operator=(volatile  Edge& other) volatile{
    	this->edgeWeight=other.edgeWeight;
    	this->vertexID=other.vertexID;
    	return *this;
    }

    __device__ bool operator>(const Edge &other)const {
        return (edgeWeight > other.edgeWeight) || ((edgeWeight == other.edgeWeight) && (vertexID > other.vertexID));
    }

    __device__ bool operator<(volatile Edge &other)volatile {
        return (edgeWeight < other.edgeWeight) || ((edgeWeight == other.edgeWeight) && (vertexID < other.vertexID));
    }

};