title: unconditional warnings when recycling
body: <p>I'll start my question by reminding what "recycling" is, and for that, I will quote another user (re: Brian Diggs' question about <a href="https://stackoverflow.com/questions/9335099/implementation-of-standard-recycling-rules">Implementation of standard recycling rules</a>):</p>
  
  <p><i>One nice feature of R which is related to its inherent vectorized nature is the recycling rule described in <a href="http://cran.r-project.org/doc/manuals/R-intro.pdf" rel="noreferrer">An Introduction to R</a> in Section 2.2.</i></p>
  
  <blockquote>
    <p>Vectors occurring in the same expression need not all be of the same length. If they are not, the value of the expression is a vector with the same length as the longest vector which occurs in the expression. Shorter vectors in the expression are recycled as often as need be (perhaps fractionally) until they match the length of the longest vector. In particular a constant is simply repeated.</p>
  </blockquote>
  
  <p>I would agree that recycling is a great feature and it makes life a lot easier. But I know a lot of people who also consider it dangerous, and I see their point: sometimes, it would be nice if R could warn you when, for example, you are trying to add a vector to a matrix, because it is not the most natural thing to do.</p>
  
  <p>My question: is it possible to make R send warnings whenever it recycles? </p>
  
  <p>Currently, R would only warn when <code>longer object length is not a multiple of shorter object length</code>. I'd like something that warns in all cases. I have looked into <code>options</code> but no luck.</p>