Concept definition

template<typename T>
concept vcl::EigenMatrixConcept =  requires (T&& obj) {
    typename RemoveRef<T>::Scalar;
 
    RemoveRef<T>();
 
    obj.RowsAtCompileTime;
    obj.ColsAtCompileTime;
 
    obj.rows();
    obj.cols();
 
    obj.operator()(std::size_t(), std::size_t());
    obj.operator()(std::size_t(), std::size_t());
 
    
    requires IsConst<T> || requires {
        obj.resize(std::size_t(), std::size_t());
        obj.conservativeResize(std::size_t(), std::size_t());
    };
}

Detailed Description

Concept for Eigen matrices. It is satisfied when T is an Eigen matrix.

The concept just checks that T has the following members:

T::RowsAtCompileTime
T::ColsAtCompileTime
T::rows()
T::cols()
T::operator()(std::size_t, std::size_t)

If the type T is non-const, it must also have the following members:

T::resize(std::size_t, std::size_t)
T::conservativeResize(std::size_t, std::size_t)

Note: The fact that an Eigen matrix has the two resize member functions does not mean that it can be resized. For example, a matrix with fixed size cannot be resized, but it has the two resize member functions, and calling them with the same sizes of the matrix does not cause any error.