13.4 — Converting an enumeration to and from a string
In the prior lesson (13.3 -- Unscoped enumerator integral conversions), we showed an example like this: #include <iostream> enum Color { black, // 0 red, // 1 blue, // 2 }; int main() { Color...
View Article13.5 — Introduction to overloading the I/O operators
In the prior lesson (13.4 -- Converting an enumeration to and from a string), we showed this example, where we used a function to convert an enumeration into an equivalent string: #include...
View Article0.13 — What language standard is my compiler using?
The following program is designed to print the name of the language standard your compiler is currently using. You can copy/paste, compile, and run this program to validate that your compiler is using...
View Article14.17 — Constexpr aggregates and classes
In lesson 5.8 -- Constexpr and consteval functions, we covered constexpr functions, which are functions that may be evaluated at either compile-time or runtime. For example: #include <iostream>...
View Article11.8 — Using function templates in multiple files
Consider the following program, which doesn’t work correctly: main.cpp: #include <iostream> template <typename T> T addOne(T x); // function template forward declaration int main() {...
View Article5.4 — The as-if rule and compile-time optimization
Introduction to optimization In programming, optimization is the process of modifying software to make it work more efficiently (e.g. to run faster, or use fewer resources). Optimization can have a...
View ArticleF.2 — Constexpr functions (part 2)
Constexpr function calls in non-required constant expressions You might expect that a constexpr function would evaluate at compile-time whenever possible, but unfortunately this is not the case. In...
View ArticleF.3 — Constexpr functions (part 3) and consteval
Forcing a constexpr function to be evaluated at compile-time There is no way to tell the compiler that a constexpr function should prefer to evaluate at compile-time whenever it can (e.g. in cases...
View ArticleF.4 — Constexpr functions (part 4)
Constexpr/consteval functions can use non-const local variables Within a constexpr or consteval function, we can use local variables that are not constexpr, and the value of these variables can be...
View ArticleF.X — Chapter F summary and quiz
A constexpr function is a function that is allowed to be called in a constant expression. To make a function a constexpr function, we simply use the constexpr keyword in front of the return type....
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