Issue getting functions from library and strange conversion error - c++

Question

I'm trying to write an arduino library. I've written a few classes before but nothing for arduino. I'm running into one error pretty consistently. First let me show you the code:
Code
Main.ino (The arduino project)
#include <Wire.h>
#include "Mobility.h"
Mobility mol = new Mobility();
void setup() {
Serial.begin(9600);
Wire.begin();
}
void loop() {
Serial.println("loop");
mol.move(true, 125, false, 125, 10);
delay(2000);
}
Mobility.h
#ifndef MOBILITY_H
#define MOBILITY_H
#if (ARDUINO >= 100)
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
const int DEFAULT_MOBILITY_ADD = 4;
class Mobility
{
public:
void begin();
void begin(int address);
int i2cAdd;
int move(bool lPos, unsigned char leftPower, bool rPos, unsigned char rightPower, unsigned char msec);
private:
};
/**/
#endif
Mobility.cpp
#if (ARDUINO >= 100)
#include "Arduino.h"
#else
#include "WProgram.h"
#endif
#include "Mobility.h"
#include "Wire.h"
void Mobility::begin(){
Wire.begin();
this.i2cAdd = DEFAULT_MOBILITY_ADD;
}
void Mobility::begin(int address){
Wire.begin();
this.i2cAdd = address;
}
int Mobility::move(bool lPos, unsigned char leftPower,bool rPos, unsigned char rightPower, unsigned char msec){
if (leftPower < -255 || leftPower > 255){
return -1;
}
if (rightPower < -255 || rightPower > 255){
return -2;
}
if(msec <= 0){
return -3;
}
Wire.beginTransmission(this.i2cAdd);
Wire.write(lPos);
Wire.write(leftPower);
Wire.write(rPos);
Wire.write(rightPower);
Wire.write(msec);
Wire.endTransmission();
return 0;
}
ERRORS
I've been getting two big errors while I've been trying to fix the code. The first is:
error: conversion from 'Mobility*' to non-scalar type 'Mobility' requested
Mobility mol = new Mobility();

Answer 1

The problem is caused by this line:
Mobility mol = new Mobility();
the first part is static memory allocation:Mobility mol - statically allocates memory for the object mol.
the second part uses dynamic memory allocation: new - dynamically allocates memory.
So you can do :
Mobility mol;// static allocation
or
Mobility *mol = new Mobility(); //dynamic allcocation
But not a mix of the two. Either way the constructor will be called when creating the object.