1 files changed, 85 insertions, 0 deletions
diff --git a/third-party/unittest/googletest/include/gtest/internal/custom/raw-ostream.h b/third-party/unittest/googletest/include/gtest/internal/custom/raw-ostream.h
new file mode 100644
index 000000000000..cff78f5c33f6
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+++ b/third-party/unittest/googletest/include/gtest/internal/custom/raw-ostream.h
@@ -0,0 +1,85 @@
+//===-- raw-ostream.h - Support for printing using raw_ostream --*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+// This file is not part of gtest, but extends it to support LLVM libraries.
+// This is not a public API for testing - it's a detail of LLVM's gtest.
+//
+// gtest allows providing printers for custom types by defining operator<<.
+// In LLVM, operator<< usually takes llvm:raw_ostream& instead of std::ostream&.
+//
+// This file defines a template printable(V), which returns a version of V that
+// can be streamed into a std::ostream.
+//
+// This interface is chosen so that in the default case (printable(V) is V),
+// the main gtest code calls operator<<(OS, V) itself. gtest-printers carefully
+// controls the lookup to enable fallback printing (see testing::internal2).
+//===----------------------------------------------------------------------===//
+
+#ifndef GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_RAW_OSTREAM_H_
+#define GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_RAW_OSTREAM_H_
+
+namespace llvm_gtest {
+// StreamSwitch is a trait that tells us how to stream a T into a std::ostream.
+// By default, we just stream the T directly. We'll specialize this later.
+template <typename T, typename Enable = void> struct StreamSwitch {
+  static const T& printable(const T& V) { return V; }
+};
+
+// printable() returns a version of its argument that can be streamed into a
+// std::ostream. This may be the argument itself, or some other representation.
+template <typename T> decltype(auto) printable(const T &V) {
+  // We delegate to the trait, to allow partial specialization.
+  return StreamSwitch<T>::printable(V);
+}
+} // namespace llvm_gtest
+
+// If raw_ostream support is enabled, we specialize for types with operator<<
+// that takes a raw_ostream.
+#if !GTEST_NO_LLVM_SUPPORT
+#include "llvm/ADT/Optional.h"
+#include "llvm/Support/raw_os_ostream.h"
+#include "llvm/Support/raw_ostream.h"
+#include <ostream>
+namespace llvm_gtest {
+
+// The printable() of a raw_ostream-enabled type T is a RawStreamProxy<T>.
+// It uses raw_os_ostream to write the wrapped value to a std::ostream.
+template <typename T>
+struct RawStreamProxy {
+  const T& V;
+  friend std::ostream &operator<<(std::ostream &S, const RawStreamProxy<T> &V) {
+    llvm::raw_os_ostream OS(S);
+    OS << V.V;
+    return S;
+  }
+};
+
+// We enable raw_ostream treatment if `(raw_ostream&) << (const T&)` is valid.
+// We don't want implicit conversions on the RHS (e.g. to bool!), so "consume"
+// the possible conversion by passing something convertible to const T& instead.
+template <typename T> struct ConvertibleTo { operator T(); };
+template <typename T>
+struct StreamSwitch<T, decltype((void)(std::declval<llvm::raw_ostream &>()
+                                       << ConvertibleTo<const T &>()))> {
+  static const RawStreamProxy<T> printable(const T &V) { return {V}; }
+};
+
+// llvm::Optional has a template operator<<, which means it will not accept any
+// implicit conversions, so we need to special-case it here.
+template <typename T>
+struct StreamSwitch<llvm::Optional<T>,
+                    decltype((void)(std::declval<llvm::raw_ostream &>()
+                                    << std::declval<llvm::Optional<T>>()))> {
+  static const RawStreamProxy<llvm::Optional<T>>
+  printable(const llvm::Optional<T> &V) {
+    return {V};
+  }
+};
+} // namespace llvm_gtest
+#endif  // !GTEST_NO_LLVM_SUPPORT
+
+#endif // GTEST_INCLUDE_GTEST_INTERNAL_CUSTOM_RAW_OSTREAM_H_