[Insight-developers] Convenience functions for Index, Offset, Point, Vector, etc.

[Brad King]

Jim,

> MakeIndex is not terribly efficient since it must construct the Index,
> set the components, and return the index but it does make the notation
> "shorter".

This should be pretty fast:

inline Index<2> MakeIndex(Index<2>::IndexValueType i0,
                          Index<2>::IndexValueType i1)
{
  Index<2> i = {{i0,i1}};
  return i;
}

Most modern compilers have a "Named Return Value Optimization" (NVRO) that
will optimize the entire call away.  The optimization was introduced to
help reduce the penalty of the common postfix-increment operator problem:

foo foo::operator++(int) { foo tmp(*this); ++*this; return tmp; }

-Brad