+ The constant <B>ERR</B> is distinct from <B>TRUE</B> and <B>FALSE</B>, which are the
+ normal return values of this function. Because the function
+ returns a <B>bool</B>, returning <B>ERR</B> (which is neither <B>TRUE</B> nor <B>FALSE</B>)
+ may not be supported by the compiler.
+
+ To provide error-checking and also match the X/Open function
+ prototype, the <B>ERR</B> is provided by a macro named <B>is_linetouched</B>.
+ The actual function returns <B>FALSE</B> when it detects an error.
+
+ <B>wtouchln</B>
+ 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 <I>win</I> to ensure that it is not <B>NULL</B>;
+ 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 <B>wtouchln</B> may be macros.
+
+
+</PRE><H2><a name="h2-SEE-ALSO">SEE ALSO</a></H2><PRE>
+ <B><A HREF="curses.3X.html">curses(3X)</A></B>, <B><A HREF="curs_refresh.3X.html">curs_refresh(3X)</A></B>, <B><A HREF="curs_variables.3X.html">curs_variables(3X)</A></B>.