Converting pointer-to-pointer to 2D array

Question

I have a function that looks like this

float Determinant(unsigned int n, float a[][n])

and I want to pass a double pointer

float **a

is there a way to cast float **a to float a[][n]?

Answer 1

No, there is no way to do that. The array a, when declared as a function parameter, decays into a pointer to the first element, an array pointer of float (*)[n]. Neither this array pointer type nor the array float a[][n] have anything to do with the type float**.

The need to pass a float** to this function probably originates from flawed program design. Perhaps you are mistaking dynamically allocated, pointer-based look-up tables for 2D arrays? If so, see Correctly allocating multi-dimensional arrays.