title: Why does `as.numeric(c(1, 1.0, "1.0", TRUE))` return `NA` for the `TRUE` element?
body: <p>Why is the <code>TRUE</code> coerced to <code>NA</code> here</p>
  <pre><code>as.numeric(c(1, 1.0, &quot;1.0&quot;, TRUE))
  </code></pre>
  <p>but not here:</p>
  <pre><code>as.numeric(c(1, 1.0, TRUE))
  </code></pre>