Clarify the return value of __nonzero__(): It *must* be an integer.

Closes SF bug #579991.

diff --git a/Doc/lib/libstdtypes.tex b/Doc/lib/libstdtypes.tex
index ca073b6b950e418308c28213c8134c1eed6680b4..1a07d3c984163637a8c987e3ecf3e61373827eb8 100644 (file)
--- a/Doc/lib/libstdtypes.tex
+++ b/Doc/lib/libstdtypes.tex
@@ -47,9 +47,9 @@ The following values are considered false:
 
 \item  instances of user-defined classes, if the class defines a
        \method{__nonzero__()} or \method{__len__()} method, when that
-       method returns zero.\footnote{Additional information on these
-special methods may be found in the \citetitle[../ref/ref.html]{Python
-Reference Manual}.}
+       method returns the integer zero.\footnote{Additional
+information on these special methods may be found in the
+\citetitle[../ref/ref.html]{Python Reference Manual}.}
 
 \end{itemize}