Modern C++ : `and`, `or` and `not` as Boolean Operators

Following my series from less known features of Modern C++.

Modern C++: An Introduction

Swastik Baranwal ・ Dec 23 '19 ・ 3 min read

#cpp #beginners #tutorial #codenewbie

In Modern C++, you can also use and, or and not as boolean operators which means &&, || and ! respectively which is identical to languages like Python. They were in C but as macros but Modern C++ introduced them as keywords.

#include <iostream>

int main() {

std::cout << true and true << std::endl;
std::cout << true or false << std::endl;
std::cout << not true << std::endl;

 return 0;
}

This is exactly identical to.

#include <iostream>

int main() {

std::cout << true && true << std::endl;
std::cout << true || false << std::endl;
std::cout << !true << std::endl;

 return 0;
}

You can probably use any one of the styles depending on your codebase.

Comments

[Idan Arye]

Why would they even do that? Even if you are not a pedantic preacher of the only-one-way-to-do-it philosophy, there should at least be a reason for having multiple ways to do it...

[Larz]

It's really disingenuous to label this "Modern" C++. It's a legacy C feature to support keyboards that didn't have all the previously accepted symbols (en.wikipedia.org/wiki/Digraphs_and...) or to make it more accessible for people with trouble inputting all the symbols.

[Jariullah Safi]

Heh, that's funny. One of my colleagues once went on an angry tirade about how "modern" C++ was ruining programming by allowing you to have a one statement if block without any surrounding curly braces...

I didn't have the heart to tell him...

[Carl Walsh]

Interesting, I knew about trigraphs but apparently they went away in C++17. and isn't strictly a C language feature: it's a language keyword in C++ but is a macro in C.

Here's more docs on the and/or/not alternative operators: en.cppreference.com/w/cpp/language...