152. Class Method Callback

In C++, you cannot pass a non-static member function (like Motor::step) directly to a handler expecting a simple function pointer, because member functions require a specific object instance (this) to operate.

Your task is to use a Lambda to "glue" a generic driver to a specific object instance.

1. Implement class Driver:
   • Member: std::function<void()> callback.
   • Method: void execute() calls the callback if valid.
   • Method: void setCallback(std::function<void()> cb).
2. Implement class Motor:
   • Member: int position (Initialize to 0).
   • Method: void step(): Increments position and prints Position: <new_pos>.
3. In main:
   • Instantiate Driver and Motor.
   • Register a lambda with the driver that captures the motor instance by reference and calls its step() method.

Program Flow:

1. Instantiate Driver and Motor.
2. Bind the motor's step function to the driver using a lambda.
3. Read integer N.
4. Loop N times.
5. Read string cmd.
6. If cmd is "TRIG", call driver.execute().

Input Format:

• First line: Integer N.
• Next N lines: String cmd ("TRIG" or other).
• Input is provided via standard input (stdin).

Output Format:

• For each "TRIG": Position: <value>
• Each output must be on a new line.

Example: 

Example 1

Input:

2
TRIG
TRIG

Output:

Position: 1
Position: 2

Constraints:

• Must use std::function in the Driver.
• Must use a lambda in main.
• Must capture motor by reference ([&]) in the lambda.