What are the new features of constexpr in C++20?

What are the new features of constexpr in C++20?

C++20 introduced several enhancements to constexpr, allowing more complex computations at compile time. For instance, you can now use dynamic memory allocation and virtual functions in constexpr contexts.

Can you give me an example of using constexpr with dynamic memory allocation?

Sure! Here's a simple example:

constexpr int* createArray(std::size_t size) {
    int* arr = new int[size];
    for (std::size_t i = 0; i < size; ++i) {
        arr[i] = i;
    }
    return arr;
}

constexpr auto myArray = createArray(5);

This code creates an array at compile time.

What are the limitations of constexpr in C++20?

Some limitations include that not all standard library functions are constexpr, and certain operations like exceptions cannot be used in constexpr functions.

How does constexpr improve performance in C++ applications?

By allowing computations to be done at compile time, constexpr can reduce runtime overhead, leading to faster execution and potentially smaller binary sizes.