static_rotation

static_rotation is a header-only library that uses template meta programming to generate all rotations of a given integer sequence at compile-time.

Example

The snippet below generates all rotations of the sequence (0,1,2,3) and stores them in a std::array<std::size_t, 16>:

#include "static_rotation.hpp"
#include <iostream>

int main() {
    using namespace static_rotation;
    using R = IndexRotations<4>;
    constexpr auto values = R::values;

    for (int i = 0; i < values.size(); i++) {
        std::cout << values[i];
        std::cout << (i % R::seq_length  == R::seq_length - 1 ? '\n' : ' ');
    }

}

The output of this snippet is

0 1 2 3
1 2 3 0
2 3 0 1
3 0 1 2

You can run the snippet on Compiler Explorer: godbolt.org/z/uNmXFr

IndexRotations<N> generates the rotations for an index sequence (0, 1, 2, ..., N). If the rotations for arbitrary sequences are needed, one may use Rotations directly, e.g.

Rotations<int, 4, 8, 15, 16, 23, 42>;

see godbolt.org/z/fWeikA for a complete example. For more details take a look at static_rotation.hpp.

Installatation

This library is header-only and including static_rotation.hpp is sufficient.

Requirements

The library uses C++17 features. No external libraries are needed.