specialize UniversalPrinter<> for std::any (without support for RTTI)

BUILD.bazel

@@ -103,6 +103,7 @@ cc_library(
             "@com_google_absl//absl/debugging:stacktrace",
             "@com_google_absl//absl/debugging:symbolize",
             "@com_google_absl//absl/strings",
+            "@com_google_absl//absl/types:any",
             "@com_google_absl//absl/types:optional",
             "@com_google_absl//absl/types:variant",
         ],

googletest/include/gtest/gtest-printers.h

@@ -679,6 +679,26 @@ class UniversalPrinter {
   GTEST_DISABLE_MSC_WARNINGS_POP_()
 };
 
+#if GTEST_INTERNAL_HAS_ANY
+
+// Printer for std::any / absl::any
+
+template <>
+class UniversalPrinter<Any> {
+ public:
+  static void Print(const Any& value, ::std::ostream* os) {
+    if (value.has_value())
+      *os << "'any' type with value of type " << GetTypeName();
+    else
+      *os << "'any' type with no value";
+  }
+
+ private:
+  static std::string GetTypeName() { return "the element type"; }
+};
+
+#endif  // GTEST_INTERNAL_HAS_ANY
+
 #if GTEST_INTERNAL_HAS_OPTIONAL
 
 // Printer for std::optional / absl::optional

googletest/include/gtest/internal/gtest-port.h

@@ -199,6 +199,8 @@
 //                                        suppressed (constant conditional).
 //   GTEST_INTENTIONAL_CONST_COND_POP_  - finish code section where MSVC C4127
 //                                        is suppressed.
+//   GTEST_INTERNAL_HAS_ANY - for enabling UniversalPrinter<std::any> or
+//                            UniversalPrinter<absl::any> specializations.
 //   GTEST_INTERNAL_HAS_OPTIONAL - for enabling UniversalPrinter<std::optional> or
 //                                 UniversalPrinter<absl::optional> specializations.
 //   GTEST_INTERNAL_HAS_STRING_VIEW - for enabling Matcher<std::string_view> or
@@ -2227,6 +2229,34 @@ const char* StringFromGTestEnv(const char* flag, const char* default_val);
 
 #endif  // !defined(GTEST_INTERNAL_DEPRECATED)
 
+#if GTEST_HAS_ABSL
+// Always use absl::any for UniversalPrinter<> specializations if googletest
+// is built with absl support.
+# define GTEST_INTERNAL_HAS_ANY 1
+#include "absl/types/any.h"
+namespace testing {
+namespace internal {
+using Any = ::absl::any;
+}  // namespace internal
+}  // namespace testing
+#else
+# ifdef __has_include
+#   if __has_include(<any>) && __cplusplus >= 201703L
+// Otherwise for C++17 and higher use std::any for UniversalPrinter<>
+// specializations.
+#   define GTEST_INTERNAL_HAS_ANY 1
+#include <any>
+namespace testing {
+namespace internal {
+using Any = ::std::any;
+}  // namespace internal
+}  // namespace testing
+// The case where absl is configured NOT to alias std::any is not
+// supported.
+#  endif  // __has_include(<any>) && __cplusplus >= 201703L
+# endif  // __has_include
+#endif  // GTEST_HAS_ABSL
+
 #if GTEST_HAS_ABSL
 // Always use absl::optional for UniversalPrinter<> specializations if googletest
 // is built with absl support.

googletest/test/googletest-printers-test.cc

@@ -1531,6 +1531,27 @@ TEST(UniversalTersePrintTupleFieldsToStringsTestWithStd, PrintsTersely) {
   EXPECT_EQ("\"a\"", result[1]);
 }
 
+#if GTEST_INTERNAL_HAS_ANY
+TEST(PrintAnyTest, Empty) {
+  internal::Any any;
+  EXPECT_EQ("'any' type with no value", PrintToString(any));
+}
+
+TEST(PrintAnyTest, NonEmpty) {
+  internal::Any any;
+  constexpr int val1 = 10;
+  const std::string val2 = "content";
+
+  any = val1;
+  EXPECT_EQ("'any' type with value of type the element type",
+            PrintToString(any));
+
+  any = val2;
+  EXPECT_EQ("'any' type with value of type the element type",
+            PrintToString(any));
+}
+#endif  // GTEST_INTERNAL_HAS_ANY
+
 #if GTEST_INTERNAL_HAS_OPTIONAL
 TEST(PrintOptionalTest, Basic) {
   internal::Optional<int> value;