Convert plain C-style casts to use CFCastStrict and GetValueFromDictionary template

net/proxy/proxy_config_service_mac.cc

Index: net/proxy/proxy_config_service_mac.cc
diff --git a/net/proxy/proxy_config_service_mac.cc b/net/proxy/proxy_config_service_mac.cc
index 2fd6ee00af687e0272de16f65bb4b31c5e5c5a82..52ddbaca869b2c3fcfd152a39a7196ed957ee077 100644
--- a/net/proxy/proxy_config_service_mac.cc
+++ b/net/proxy/proxy_config_service_mac.cc
@@ -8,6 +8,7 @@
 #include <SystemConfiguration/SystemConfiguration.h>
 
 #include "base/logging.h"
+#include "base/mac/foundation_util.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/message_loop.h"
@@ -28,8 +29,9 @@ const int kPollIntervalSec = 5;
 bool GetBoolFromDictionary(CFDictionaryRef dict,
                            CFStringRef key,
                            bool default_value) {
-  CFNumberRef number = (CFNumberRef)base::mac::GetValueFromDictionary(
-      dict, key, CFNumberGetTypeID());
+  CFNumberRef number =
+      base::mac::CFCastStrict<CFNumberRef>(

[Ryan Sleevi, 2011/11/11 00:26:42]

nit: You can align this to the previous line, and then you only have to indent
line 34 by four spaces, rather than 8.

This also applies to the following lines: 65-70, 137-140

However, I don't believe any of these casts are needed to be strict (except for
144/145), as GetValueFromDictionary already asserts that the returned type is
the same as the expected type.

If they aren't, it will DLOG(ERROR) and return NULL, which accomplishes the same
as the Strict check.

So perhaps just CFCast these?

[KushalP, 2011/11/11 11:03:19]

In the case of GetValueFromDictionary() it should definitely use the Strict case
as we've already partially told it what to expect in the bucket.

I'll update the CFArrayGetValueAtIndex cases to use the non-strict variant.

On 2011/11/11 00:26:42, Ryan Sleevi wrote:

[Ryan Sleevi, 2011/11/11 17:23:11]

I think you misunderstood. I believe CFArrayGetValueAtIndex *should* be using
the strict.

However, please examine the implementation of GetValueFromDictionary. You'll see
that it's already doing strict checks - if the value it extracts from the
dictionary is not of the same CFType requested, it will DLOG(WARNING) and return
NULL.

+          base::mac::GetValueFromDictionary(dict, key, CFNumberGetTypeID()));
   if (!number)
     return default_value;
 
@@ -60,10 +62,12 @@ void GetCurrentProxyConfig(ProxyConfig* config) {
   if (GetBoolFromDictionary(config_dict.get(),
                             kSCPropNetProxiesProxyAutoConfigEnable,
                             false)) {
-    CFStringRef pac_url_ref = (CFStringRef)base::mac::GetValueFromDictionary(
-        config_dict.get(),
-        kSCPropNetProxiesProxyAutoConfigURLString,
-        CFStringGetTypeID());
+    CFStringRef pac_url_ref =
+        base::mac::CFCastStrict<CFStringRef>(
+            base::mac::GetValueFromDictionary(
+                config_dict.get(),
+                kSCPropNetProxiesProxyAutoConfigURLString,
+                CFStringGetTypeID()));
     if (pac_url_ref)
       config->set_pac_url(GURL(base::SysCFStringRefToUTF8(pac_url_ref)));
   }
@@ -130,15 +134,15 @@ void GetCurrentProxyConfig(ProxyConfig* config) {
   // proxy bypass list
 
   CFArrayRef bypass_array_ref =
-      (CFArrayRef)base::mac::GetValueFromDictionary(
+      base::mac::CFCastStrict<CFArrayRef>(base::mac::GetValueFromDictionary(
           config_dict.get(),
           kSCPropNetProxiesExceptionsList,
-          CFArrayGetTypeID());
+          CFArrayGetTypeID()));
   if (bypass_array_ref) {
     CFIndex bypass_array_count = CFArrayGetCount(bypass_array_ref);
     for (CFIndex i = 0; i < bypass_array_count; ++i) {
-      CFStringRef bypass_item_ref =
-          (CFStringRef)CFArrayGetValueAtIndex(bypass_array_ref, i);
+      CFStringRef bypass_item_ref = base::mac::CFCastStrict<CFStringRef>(
+              CFArrayGetValueAtIndex(bypass_array_ref, i));
       if (CFGetTypeID(bypass_item_ref) != CFStringGetTypeID()) {
         LOG(WARNING) << "Expected value for item " << i
                      << " in the kSCPropNetProxiesExceptionsList"