pub fn grow_expansion(
e: &[f64],
b: f64,
h: &mut [f64],
) -> Result<usize, ExpansionError>Expand description
Grow an expansion by adding a scalar: h = e + b.
e is the input expansion (length elen), b is the scalar, h is the
output buffer (must have length >= elen + 1). Returns the number of
components written to h (always elen + 1).
Implements Shewchuk’s grow_expansion (§2.4): a single pass that merges
b into the expansion using fast_two_sum, maintaining the
non-overlapping + sorted invariant.
§Errors
Returns ExpansionError::OutputTooSmall if h.len() < elen + 1.