Function BTree.getMinDegree
Gets the minimum degree of the B-Tree.
static size_t getMinDegree() pure nothrow @nogc @safe;
The B-Tree is defined by a minimum degree "t". Each node other than the root must have at least t-1 values. Each node may have up to 2t - 1 values, thus an internal node may have up to 2*t children.
Thus, the maximum size of a non-leaf node is: - [values] (2t-1) * (size of a value) - [numValues] + 1 * (size of size_t) - [isLeaf] + 1 * (size of a bool) - [children] + 2*t * (size of pointer to a node) - = NodeSize