https://learncodethehardway.com/courses/learn-cpp-the-hard-way/2-beginner-c/27-references-vs-copying-and-functions/
Learn C++ the Hard Way: 27: References vs. Copying and Functions
References and Copying for Function Parameters
learn c the hard way
https://learncodethehardway.com/courses/learn-cpp-the-hard-way/3-intermediate-c/58-constructors-and-destructors/
Learn C++ the Hard Way: 58: Constructors and Destructors
Constructors and Destructors
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