Description
In this workshop, you are to compare move and copy operations on an object that contains a dynamically allocated array of string objects.
LEARNING OUTCOMES
Upon successful completion of this workshop, you will have demonstrated the abilities to
- implement copy semantics for a class with a resource
- implement move semantics for a class with a resource
- identify the processing-intensive operations in copy and move assignments
- retrieve data from a text file using an ifstream object
SPECIFICATIONS
Text Class
Design and code a class named Text that manages a dynamically allocated array of strings. Upon instantiation, a Text object receives nothing or a reference to an unmodifiable string. The string holds the name of the text file that contains the records to be stored in an object of this class. If the file does not exist, the Text object assumes a safe empty state. If the file exists, the one-argument constructor allocates memory for the number of lines contained in the file and copies them into memory. To review the syntax for reading from a text file using an ifstream object see the chapter in your notes entitled Custom File Operators. See also cplusplus.com
Your design also includes the following member functions:
- a copy constructor
- a copy assignment operator
- a move constructor
- a move assignment operator
- a destructor
- a member function named size_t size() const that returns the number of records of text data
Define your class and its implementation in namespace w3. Store your class definition in a header file named Text.h and your member function definitions in an implementation file named Text.cpp.
Input
A text file named gutenberg_shakespeare is available with this lab. Make sure you include this file as a command line argument.
Output
The output of this program is based on the speed and processing power of the machine that it’s being run on. What you are looking for in the output is the following:
- Size of all the objects should be the same
- Copy operations should be slower than move operations
EXAMPLE
Default Constructor 380 nanoseconds – a.size = 0
Custom Constructor 9982078037 nanoseconds – b.size = 124457
Copy Assignment 422828094 nanoseconds – a.size = 124457
Move Assignment 761 nanoseconds – a.size = 124457
Copy Constructor 399876151 nanoseconds – c.size = 124457
Move Constructor 1141 nanoseconds – d.size = 124457
Destructor 429119369 nanoseconds
