Terse printing of std::reference_wrapper hides pointer

This matches the intention and documentation of terse printing which generally avoids printing the pointer.

PiperOrigin-RevId: 481178950
Change-Id: I27039dac1870934d2d5b212e2cc7e97ab82c5b34

Author: Abseil Team

googletest/include/gtest/gtest-printers.h

@@ -891,6 +891,13 @@ class UniversalTersePrinter<T&> {
     UniversalPrint(value, os);
   }
 };
+template <typename T>
+class UniversalTersePrinter<std::reference_wrapper<T>> {
+ public:
+  static void Print(std::reference_wrapper<T> value, ::std::ostream* os) {
+    UniversalTersePrinter<T>::Print(value.get(), os);
+  }
+};
 template <typename T, size_t N>
 class UniversalTersePrinter<T[N]> {
  public:

googletest/test/googletest-printers-test.cc

@@ -37,6 +37,7 @@
 #include <cstring>
 #include <deque>
 #include <forward_list>
+#include <functional>
 #include <limits>
 #include <list>
 #include <map>
@@ -193,6 +194,11 @@ OutputStream& operator<<(OutputStream& os,
   return os;
 }
 
+struct StreamableInLocal {};
+void operator<<(::std::ostream& os, const StreamableInLocal& /* x */) {
+  os << "StreamableInLocal";
+}
+
 // A user-defined streamable but recursively-defined container type in
 // a user namespace, it mimics therefore std::filesystem::path or
 // boost::filesystem::path.
@@ -1604,6 +1610,23 @@ TEST(PrintToStringTest, ContainsNonLatin) {
                           "\n    As Text: \"From ä — ẑ\"");
 }
 
+TEST(PrintToStringTest, PrintStreamableInLocal) {
+  EXPECT_STREQ("StreamableInLocal",
+               PrintToString(foo::StreamableInLocal()).c_str());
+}
+
+TEST(PrintToStringTest, PrintReferenceToStreamableInLocal) {
+  foo::StreamableInLocal s;
+  std::reference_wrapper<foo::StreamableInLocal> r(s);
+  EXPECT_STREQ("StreamableInLocal", PrintToString(r).c_str());
+}
+
+TEST(PrintToStringTest, PrintReferenceToStreamableInGlobal) {
+  StreamableInGlobal s;
+  std::reference_wrapper<StreamableInGlobal> r(s);
+  EXPECT_STREQ("StreamableInGlobal", PrintToString(r).c_str());
+}
+
 TEST(IsValidUTF8Test, IllFormedUTF8) {
   // The following test strings are ill-formed UTF-8 and are printed
   // as hex only (or ASCII, in case of ASCII bytes) because IsValidUTF8() is