How do I use constexpr and consteval?

In C++, `constexpr` and `consteval` are used to define variables and functions whose values can be evaluated at compile time. This allows for optimization and can lead to more efficient code.

`constexpr` is used to declare functions or variables that can be evaluated at compile time. It was introduced in C++11 and has been enhanced in subsequent versions. On the other hand, `consteval`, introduced in C++20, ensures that a function is evaluated at compile time, and can not be used at runtime.

Here's an example illustrating the use of `constexpr` and `consteval`:

// Example of constexpr and consteval in C++ #include // constexpr function constexpr int square(int x) { return x * x; } // consteval function consteval int cube(int x) { return x * x * x; } int main() { constexpr int x = 5; std::cout << "Square of " << x << " is: " << square(x) << std::endl; // evaluated at compile time std::cout << "Cube of " << x << " is: " << cube(x) << std::endl; // evaluated at compile time return 0; }

constexpr consteval C++ compile-time evaluation C++ functions

Related Questions

How do I avoid rehashing overhead with std::set in multithreaded code?

How do I find elements with custom comparators with std::set for embedded targets?

How do I erase elements while iterating with std::set for embedded targets?

How do I provide stable iteration order with std::unordered_map for large datasets?

How do I reserve capacity ahead of time with std::unordered_map for large datasets?

How do I erase elements while iterating with std::unordered_map in multithreaded code?

How do I provide stable iteration order with std::map for embedded targets?

How do I provide stable iteration order with std::map in multithreaded code?

How do I avoid rehashing overhead with std::map in performance-sensitive code?

How do I merge two containers efficiently with std::map for embedded targets?