From ac3c2a8d0496893787015014a5abd397b766cce2 Mon Sep 17 00:00:00 2001
From: Niels Dekker <N.Dekker@lumc.nl>
Date: Thu, 24 Dec 2020 13:42:39 +0100
Subject: [PATCH] overload PrintTo for std::type_info and std::type_index

Included the string returned by their `name()` member function with the output of `PrintTo`.

Typical use case:

    std::unique_ptr<AbstractProduct> product = FactoryMethod();
    // Assert that the product is of type X:
    ASSERT_EQ(std::type_index{typeid(*product)},
              std::type_index{typeid(ProductX)});

Possible output in case of a test assert failure, now including the names of the compared type indices:

> error: Expected equality of these values:
>  std::type_index(typeid(*product))
>    Which is: 8-byte object <D0-65 54-8C F6-7F 00-00> ("class ProductY")
>  std::type_index(typeid(ProductX))
>    Which is: 8-byte object <40-64 54-8C F6-7F 00-00> ("class ProductX")

With help from Krystian Kuzniarek.
---
 googletest/include/gtest/gtest-printers.h   | 23 ++++++++++++++
 googletest/test/googletest-printers-test.cc | 34 +++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/googletest/include/gtest/gtest-printers.h b/googletest/include/gtest/gtest-printers.h
index cd094949..aa9ca48c 100644
--- a/googletest/include/gtest/gtest-printers.h
+++ b/googletest/include/gtest/gtest-printers.h
@@ -113,6 +113,11 @@
 #include "gtest/internal/gtest-internal.h"
 #include "gtest/internal/gtest-port.h"
 
+#if GTEST_HAS_RTTI
+#include <typeindex>
+#include <typeinfo>
+#endif  // GTEST_HAS_RTTI
+
 namespace testing {
 
 // Definitions in the internal* namespaces are subject to change without notice.
@@ -650,6 +655,24 @@ void PrintTo(const ::std::pair<T1, T2>& value, ::std::ostream* os) {
   *os << ')';
 }
 
+template <typename T>
+void PrintWithNameTo(const T& value, ::std::ostream* os) {
+  internal::PrintTo<T>(value, os);
+  *os << " (\"" << value.name() << "\")";
+}
+
+#if GTEST_HAS_RTTI
+
+inline void PrintTo(const ::std::type_info& value, ::std::ostream* os) {
+  internal::PrintWithNameTo(value, os);
+}
+
+inline void PrintTo(const ::std::type_index& value, ::std::ostream* os) {
+  internal::PrintWithNameTo(value, os);
+}
+
+#endif  // GTEST_HAS_RTTI
+
 // Implements printing a non-reference type T by letting the compiler
 // pick the right overload of PrintTo() for T.
 template <typename T>
diff --git a/googletest/test/googletest-printers-test.cc b/googletest/test/googletest-printers-test.cc
index 8247d4e1..1d35c549 100644
--- a/googletest/test/googletest-printers-test.cc
+++ b/googletest/test/googletest-printers-test.cc
@@ -1589,6 +1589,40 @@ TEST(PrintToStringTest, WorksForCharArrayWithEmbeddedNul) {
                           "\n    As Text: \"From ä — ẑ\"");
 }
 
+#if GTEST_HAS_RTTI
+TEST(PrintToStringTest, IncludesNameWithTypeInfoAndTypeIndex) {
+  // The following lambda tests that both the printed string for the specified
+  // `typeid`, and the one for its `std::type_index` contain the string returned
+  // by its `name()` member function.
+  const auto TestTypeId = [](const ::std::type_info& id) {
+    const auto name = id.name();
+    const auto contains_name = [name](const ::std::string& str) {
+      return str.find(name) != ::std::string::npos;
+    };
+    EXPECT_TRUE(contains_name(PrintToString(id)));
+    EXPECT_TRUE(contains_name(PrintToString(::std::type_index{id})));
+  };
+
+  TestTypeId(typeid(void));
+  TestTypeId(typeid(int));
+  TestTypeId(typeid(const volatile int*));
+
+  struct Base {
+    virtual ~Base() = default;
+  };
+  struct Derived : Base {};
+
+  TestTypeId(typeid(Base));
+  TestTypeId(typeid(Derived));
+
+  Derived derived;
+  Base& base = derived;
+
+  TestTypeId(typeid(base));
+  TestTypeId(typeid(derived));
+}
+#endif  // GTEST_HAS_RTTI
+
 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