title: AM_CONDITIONAL testing size of type
body: <p>I would like to define <code>PLATFORM64</code> if <code>SIZEOF_VOIDP</code> equals 8, the configure snippet below don't work but shows what I would like to achieve. Is there a way of doing this in my configure script? </p>
  
  <pre><code># Get size of void*
  AC_CHECK_SIZEOF(void*)
  
  # Determine if this is a 32 or 64 bit system, this can also be set manually with "-DPLATFORM64"
  AM_CONDITIONAL([PLATFORM64], [test SIZEOF_VOIDP = 8])
  </code></pre>
  
  <p><strong>Update:</strong></p>
  
  <p>I've tried:</p>
  
  <pre><code>AM_CONDITIONAL([PLATFORM64], [test "$SIZEOF_VOIDP" -eq 8])
  </code></pre>
  
  <p>but I get "test: bad number" error message.</p>