2 files changed, 25 insertions, 17 deletions

diff --git a/include/gtest/gtest-printers.h b/include/gtest/gtest-printers.h
index a86a4a34..c8daa294 100644
--- a/include/gtest/gtest-printers.h
+++ b/include/gtest/gtest-printers.h
@@ -404,22 +404,22 @@ GTEST_API_ void PrintTo(wchar_t wc, ::std::ostream* os);
 // Overloads for C strings.
 GTEST_API_ void PrintTo(const char* s, ::std::ostream* os);
 inline void PrintTo(char* s, ::std::ostream* os) {
-  PrintTo(implicit_cast<const char*>(s), os);
+  PrintTo(ImplicitCast_<const char*>(s), os);
 }
 
 // signed/unsigned char is often used for representing binary data, so
 // we print pointers to it as void* to be safe.
 inline void PrintTo(const signed char* s, ::std::ostream* os) {
-  PrintTo(implicit_cast<const void*>(s), os);
+  PrintTo(ImplicitCast_<const void*>(s), os);
 }
 inline void PrintTo(signed char* s, ::std::ostream* os) {
-  PrintTo(implicit_cast<const void*>(s), os);
+  PrintTo(ImplicitCast_<const void*>(s), os);
 }
 inline void PrintTo(const unsigned char* s, ::std::ostream* os) {
-  PrintTo(implicit_cast<const void*>(s), os);
+  PrintTo(ImplicitCast_<const void*>(s), os);
 }
 inline void PrintTo(unsigned char* s, ::std::ostream* os) {
-  PrintTo(implicit_cast<const void*>(s), os);
+  PrintTo(ImplicitCast_<const void*>(s), os);
 }
 
 // MSVC can be configured to define wchar_t as a typedef of unsigned
@@ -431,7 +431,7 @@ inline void PrintTo(unsigned char* s, ::std::ostream* os) {
 // Overloads for wide C strings
 GTEST_API_ void PrintTo(const wchar_t* s, ::std::ostream* os);
 inline void PrintTo(wchar_t* s, ::std::ostream* os) {
-  PrintTo(implicit_cast<const wchar_t*>(s), os);
+  PrintTo(ImplicitCast_<const wchar_t*>(s), os);
 }
 #endif
 
diff --git a/include/gtest/internal/gtest-port.h b/include/gtest/internal/gtest-port.h
index 900a41dc..be2297ed 100644
--- a/include/gtest/internal/gtest-port.h
+++ b/include/gtest/internal/gtest-port.h
@@ -919,25 +919,29 @@ inline void FlushInfoLog() { fflush(NULL); }
 
 // INTERNAL IMPLEMENTATION - DO NOT USE IN USER CODE.
 //
-// Use implicit_cast as a safe version of static_cast for upcasting in
+// Use ImplicitCast_ as a safe version of static_cast for upcasting in
 // the type hierarchy (e.g. casting a Foo* to a SuperclassOfFoo* or a
-// const Foo*).  When you use implicit_cast, the compiler checks that
-// the cast is safe.  Such explicit implicit_casts are necessary in
+// const Foo*).  When you use ImplicitCast_, the compiler checks that
+// the cast is safe.  Such explicit ImplicitCast_s are necessary in
 // surprisingly many situations where C++ demands an exact type match
 // instead of an argument type convertable to a target type.
 //
-// The syntax for using implicit_cast is the same as for static_cast:
+// The syntax for using ImplicitCast_ is the same as for static_cast:
 //
-//   implicit_cast<ToType>(expr)
+//   ImplicitCast_<ToType>(expr)
 //
-// implicit_cast would have been part of the C++ standard library,
+// ImplicitCast_ would have been part of the C++ standard library,
 // but the proposal was submitted too late.  It will probably make
 // its way into the language in the future.
+//
+// This relatively ugly name is intentional. It prevents clashes with
+// similar functions users may have (e.g., implicit_cast). The internal
+// namespace alone is not enough because the function can be found by ADL.
 template<typename To>
-inline To implicit_cast(To x) { return x; }
+inline To ImplicitCast_(To x) { return x; }
 
 // When you upcast (that is, cast a pointer from type Foo to type
-// SuperclassOfFoo), it's fine to use implicit_cast<>, since upcasts
+// SuperclassOfFoo), it's fine to use ImplicitCast_<>, since upcasts
 // always succeed.  When you downcast (that is, cast a pointer from
 // type Foo to type SubclassOfFoo), static_cast<> isn't safe, because
 // how do you know the pointer is really of type SubclassOfFoo?  It
@@ -953,15 +957,19 @@ inline To implicit_cast(To x) { return x; }
 //    if (dynamic_cast<Subclass1>(foo)) HandleASubclass1Object(foo);
 //    if (dynamic_cast<Subclass2>(foo)) HandleASubclass2Object(foo);
 // You should design the code some other way not to need this.
-template<typename To, typename From>  // use like this: down_cast<T*>(foo);
-inline To down_cast(From* f) {  // so we only accept pointers
+//
+// This relatively ugly name is intentional. It prevents clashes with
+// similar functions users may have (e.g., down_cast). The internal
+// namespace alone is not enough because the function can be found by ADL.
+template<typename To, typename From>  // use like this: DownCast_<T*>(foo);
+inline To DownCast_(From* f) {  // so we only accept pointers
   // Ensures that To is a sub-type of From *.  This test is here only
   // for compile-time type checking, and has no overhead in an
   // optimized build at run-time, as it will be optimized away
   // completely.
   if (false) {
     const To to = NULL;
-    ::testing::internal::implicit_cast<From*>(to);
+    ::testing::internal::ImplicitCast_<From*>(to);
   }
 
 #if GTEST_HAS_RTTI