X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=docs%2Fusers_guide%2Fusing.xml;h=22c886100f276ff6666d228d5502164b525ac7c0;hp=be8232244bcab976ae5db065ce986e3d010f73cb;hb=0656c72a8f4fda30c348bdf40449d105e4ce00ce;hpb=e21c922fcdd1dac193bd8ff5670787daa3c21a12

diff --git a/docs/users_guide/using.xml b/docs/users_guide/using.xml
index be82322..22c8861 100644
--- a/docs/users_guide/using.xml
+++ b/docs/users_guide/using.xml
@@ -1175,6 +1175,21 @@ foreign import "&f" f :: FunPtr t
       </varlistentry>
 
       <varlistentry>
+        <term><option>-fwarn-identities</option>:</term>
+	<listitem>
+          <indexterm><primary><option>-fwarn-identities</option></primary></indexterm>
+          <para>Causes the compiler to emit a warning when a Prelude numeric
+            conversion converts a type T to the same type T; such calls
+            are probably no-ops and can be omitted.  The functions checked for
+            are: <literal>toInteger</literal>,
+            <literal>toRational</literal>,
+            <literal>fromIntegral</literal>,
+            and <literal>realToFrac</literal>.
+          </para>
+	</listitem>
+      </varlistentry>
+
+      <varlistentry>
         <term><option>-fwarn-implicit-prelude</option>:</term>
         <listitem>
           <indexterm><primary><option>-fwarn-implicit-prelude</option></primary></indexterm>