Merge pull request #3163 from WalterBright/crc32Of-doc

Improve documentation for std.digest.crc.crc32Of

std/digest/crc.d

@@ -308,13 +308,37 @@ unittest
 /**
  * This is a convenience alias for $(XREF digest.digest, digest) using the
  * CRC32 implementation.
+ *
+ * Params:
+ *      data = $(D InputRange) of $(D ElementType) implicitly convertible to $(D ubyte), $(D ubyte[]) or $(D ubyte[num]
+ *             or one or more arrays of any type.
+ *
+ * Returns:
+ *      CRC32 of data
  */
 //simple alias doesn't work here, hope this gets inlined...
-auto crc32Of(T...)(T data)
+ubyte[4] crc32Of(T...)(T data)
 {
     return digest!(CRC32, T)(data);
 }
 
+///
+unittest
+{
+    ubyte[] data = [4,5,7,25];
+    assert(data.crc32Of == [167, 180, 199, 131]);
+
+    import std.utf : byChar;
+    assert("hello"d.byChar.crc32Of == [134, 166, 16, 54]);
+
+    ubyte[4] hash = "abc".crc32Of();
+    assert(hash == digest!CRC32("ab", "c"));
+
+    import std.range : iota;
+    enum ubyte S = 5, F = 66;
+    assert(iota(S, F).crc32Of == [59, 140, 234, 154]);
+}
+
 /**
  * This is a convenience alias for $(XREF digest.digest, toHexString) producing the usual
  * CRC32 string output.
@@ -323,12 +347,6 @@ public alias crcHexString = toHexString!(Order.decreasing);
 ///ditto
 public alias crcHexString = toHexString!(Order.decreasing, 16);
 
-///
-unittest
-{
-    ubyte[4] hash = crc32Of("abc");
-    assert(hash == digest!CRC32("abc")); //This is the same as above
-}
 
 /**
  * OOP API CRC32 implementation.