public MutableTransposeNdArrayImpl(MutableNdArrayImpl <T> source, ReadOnlySpan <int> axisMap)
: base(TransposeShape(source.Shape, axisMap))
{
_source = source;
_axisMap = axisMap.ToArray();
}
// This function is defined to limit lifetime of stackalloc. // Do not expand inline this local function. static void exchange(MutableNdArrayImpl <T> p, int j, (int, int) perm)
