C++ Brain Teasers

Puzzle 9

Counting Copies

counting-copies.cpp

#include <iostream>

struct Resource
{
    Resource() = default;
    Resource(const Resource &other)
    {
        std::cout << "copy\n";
    }
};

Resource getResource()
{
    return Resource{};
}

int main()
{
    Resource resource1 = getResource();
    Resource resource2{resource1};
}

Guess the Output
	Try to guess what the output is before moving to the next page.

The program displays the following output:

copy

Discussion

It may seem like three copies are being made in this program. ...