+ The constant <STRONG>ERR</STRONG> is distinct from <STRONG>TRUE</STRONG> and <STRONG>FALSE</STRONG>, which are the
+ normal return values of this function. Because the function
+ returns a <STRONG>bool</STRONG>, returning <STRONG>ERR</STRONG> (which is neither <STRONG>TRUE</STRONG> nor <STRONG>FALSE</STRONG>)
+ may not be supported by the compiler.
+
+ To provide error-checking and also match the X/Open function
+ prototype, the <STRONG>ERR</STRONG> is provided by a macro named <STRONG>is_linetouched</STRONG>.
+ The actual function returns <STRONG>FALSE</STRONG> when it detects an error.
+
+ <STRONG>wtouchln</STRONG>
+ returns an error if the window pointer is null, or if the line
+ number is outside the window.
+
+
+</PRE><H2><a name="h2-PORTABILITY">PORTABILITY</a></H2><PRE>
+ These functions were introduced by SVr4. The Solaris curses header
+ file, for instance, defines both an actual function and macro for each.
+ The macros give the same result as the actual functions. SVr4 curses
+ does not check the window parameter <EM>win</EM> to ensure that it is not <STRONG>NULL</STRONG>;
+ otherwise this implementation behaves the same as SVr4.
+
+ The XSI Curses standard, Issue 4 describes these functions, but defines
+ no error conditions.
+
+
+</PRE><H2><a name="h2-NOTES">NOTES</a></H2><PRE>
+ All of these routines except <STRONG>wtouchln</STRONG> may be macros.
+
+
+</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>