pre and post condition in function

Bjarne Stroustrup “Programming Principles and Practice Using C++”
Chapter 5 Try This page 166
Using std_lib_facilities.h by Bjarne Stroustrup.

//	Philipp Siedler
//	Bjarne Stroustrup's PP
//	Chapter 5 Try This page 166

#include "std_lib_facilities.h"

int area(int length, int width) {
	if (length <= 0 || width <= 0) {
		error("area() pre-condition");
	}

	int a = length * width;

	if (a <= 0) {
		error("area() post-condition");
	}
	return a;
}

int main()
try
{
	int area1;
	area1 = area(60000, 60000);
	cout << area1;

	keep_window_open("x");
}
catch (exception& e) {
	cerr << "error: " << e.what() << '\n';
	keep_window_open();
	return 1;
}
catch (...) {
	cerr << "Unknown exception!\n";
	keep_window_open();
	return 2;
}
Output:
High temperature: 42.6
Low temperature: -26.1
Average temperature: 9.28333

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.