Comment and include guard

src/dsp/FFT.h

@@ -46,6 +46,8 @@ class FFTImpl;
  * size/2+1 real+imaginary pairs.  So, the array elements at indices 1
  * and size+1 will always be zero (since the signal is real).
  *
+ * Neither forward nor inverse transform is scaled.
+ *
  * This class is reentrant but not thread safe: use a separate
  * instance per thread, or use a mutex.
  */

src/float_cast/float_cast.h

@@ -1,3 +1,6 @@
+#ifndef ERIKD_FLOATCAST_H
+#define ERIKD_FLOATCAST_H
+
 /*
 ** Copyright (C) 2001 Erik de Castro Lopo <erikd AT mega-nerd DOT com>
 **
@@ -69,5 +72,4 @@
 
 #endif
 
-
-
+#endif