The Parameter of a Copy Constructor Must be Passed by Reference

The canonical form of a copy constructor of a class C is:

   C::C(const C& rhs);

You can also declare the copy constructor’s parameter as follows:

   C::C(C& rhs); //no const, OK

That is, the const specifier is not mandatory. However, the parameter may not be passed by value:

   C::C(const C rhs); //Error: parameter passed by value

Can you see why the parameter must be passed by reference? Whenever you pass an object by value, you implicitly invoke its copy constructor, because the object passed is a copy of the original argument. The result is an infinite recursion: the copy constructor calls another copy constructor, which in turn calls another copy constructor and so on. To avoid this infinite recursion, C++ requires that a copy constructor’s parameter be passed by reference.

Share the Post:
Share on facebook
Share on twitter
Share on linkedin


The Latest

homes in the real estate industry

Exploring the Latest Tech Trends Impacting the Real Estate Industry

The real estate industry is changing thanks to the newest technological advancements. These new developments — from blockchain and AI to virtual reality and 3D printing — are poised to change how we buy and sell homes. Real estate brokers, buyers, sellers, wholesale real estate professionals, fix and flippers, and beyond may

man on floor with data

DevX Quick Guide to Data Ingestion

One of the biggest trends of the 21st century is the massive surge in internet usage. With major innovations such as smart technology, social media, and online shopping sites, the internet has become an essential part of everyday life for a large portion of the population. Due to this internet

payment via phone

7 Ways Technology Has Changed Traditional Payments

In today’s digital world, technology has changed how we make payments. From contactless cards to mobile wallets, it’s now easier to pay for goods and services without carrying cash or using a checkbook. This article will look at seven of the most significant ways technology has transformed traditional payment methods.