How to Initialize a C 11 `constexpr` Array from 0 to N?

Initializing a Constexpr Array from 0 to N in C 11

In C 11, creating a constexpr array that spans from 0 to a specified integer n requires a bit more effort than in later C versions. Here's how it can be done:

Using a Constexpr Constructor and a Loop:

#include <iostream>

template<int N>
struct Array {
    constexpr Array() : arr() {
        for (auto i = 0; i != N; ++i)
            arr[i] = i;
    }
    int arr[N];
};

int main() {
    constexpr auto a = Array<5>();
    for (auto x : a.arr)
        std::cout << x << '\n';
}

In this code:

• The Array struct template represents the constexpr array.
• The constexpr constructor initializes the array elements from 0 to N-1, using a loop.
• In main(), an instance of Array<5> is created, and its elements are printed to the console. This should output 0, 1, 2, 3, 4.

The above is the detailed content of How to Initialize a C 11 `constexpr` Array from 0 to N?. For more information, please follow other related articles on the PHP Chinese website!