code: func (elems elemArr) grow(n int) []elemType {
  	if cap(elems) < n {
  		elems = make([]elemType, n)
  	}
  	elems = elems[:n]
  	// following compiler optimized memcpy impl
  	// https://github.com/golang/go/wiki/CompilerOptimizations#optimized-memclr
  	var empty elemType
  	for i := range elems {
  		elems[i] = empty
  	}
  	return elems
  }
docs: // nolint