--- /dev/null
+// ----------------------------------------------------------------------------
+// $Id$
+// ----------------------------------------------------------------------------
+// Public Domain C Library - http://pdclib.sourceforge.net
+// This code is Public Domain. Use, modify, and redistribute at will.
+// ----------------------------------------------------------------------------
+
+// ----------------------------------------------------------------------------
+// C++
+
+float atan( float x ) { /* TODO */ };
+long double atan( long double x ) { /* TODO */ };
+
+// ----------------------------------------------------------------------------
+// Standard C
+
+double atan( double x ) { /* TODO */ };
+float atanf( float x ) { /* TODO */ };
+long double atanl( long double x ) { /* TODO */ };