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31 // Google Test - The Google C++ Testing and Mocking Framework
33 // This file implements a universal value printer that can print a
34 // value of any type T:
36 // void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
38 // A user can teach this function how to print a class type T by
39 // defining either operator<<() or PrintTo() in the namespace that
40 // defines T. More specifically, the FIRST defined function in the
41 // following list will be used (assuming T is defined in namespace
44 // 1. foo::PrintTo(const T&, ostream*)
45 // 2. operator<<(ostream&, const T&) defined in either foo or the
48 // However if T is an STL-style container then it is printed element-wise
49 // unless foo::PrintTo(const T&, ostream*) is defined. Note that
50 // operator<<() is ignored for container types.
52 // If none of the above is defined, it will print the debug string of
53 // the value if it is a protocol buffer, or print the raw bytes in the
56 // To aid debugging: when T is a reference type, the address of the
57 // value is also printed; when T is a (const) char pointer, both the
58 // pointer value and the NUL-terminated string it points to are
61 // We also provide some convenient wrappers:
63 // // Prints a value to a string. For a (const or not) char
64 // // pointer, the NUL-terminated string (but not the pointer) is
66 // std::string ::testing::PrintToString(const T& value);
68 // // Prints a value tersely: for a reference type, the referenced
69 // // value (but not the address) is printed; for a (const or not) char
70 // // pointer, the NUL-terminated string (but not the pointer) is
72 // void ::testing::internal::UniversalTersePrint(const T& value, ostream*);
74 // // Prints value using the type inferred by the compiler. The difference
75 // // from UniversalTersePrint() is that this function prints both the
76 // // pointer and the NUL-terminated string for a (const or not) char pointer.
77 // void ::testing::internal::UniversalPrint(const T& value, ostream*);
79 // // Prints the fields of a tuple tersely to a string vector, one
80 // // element for each field. Tuple support must be enabled in
82 // std::vector<string> UniversalTersePrintTupleFieldsToStrings(
83 // const Tuple& value);
87 // The print primitives print the elements of an STL-style container
88 // using the compiler-inferred type of *iter where iter is a
89 // const_iterator of the container. When const_iterator is an input
90 // iterator but not a forward iterator, this inferred type may not
91 // match value_type, and the print output may be incorrect. In
92 // practice, this is rarely a problem as for most containers
93 // const_iterator is a forward iterator. We'll fix this if there's an
94 // actual need for it. Note that this fix cannot rely on value_type
95 // being defined as many user-defined container types don't have
98 // GOOGLETEST_CM0001 DO NOT DELETE
100 #ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
101 #define GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
103 #include <functional>
105 #include <ostream> // NOLINT
109 #include <type_traits>
113 #include "gtest/internal/gtest-internal.h"
114 #include "gtest/internal/gtest-port.h"
118 // Definitions in the internal* namespaces are subject to change without notice.
119 // DO NOT USE THEM IN USER CODE!
122 template <typename T>
123 void UniversalPrint(const T& value, ::std::ostream* os);
125 // Used to print an STL-style container when the user doesn't define
126 // a PrintTo() for it.
127 struct ContainerPrinter {
128 template <typename T,
129 typename = typename std::enable_if<
130 (sizeof(IsContainerTest<T>(0)) == sizeof(IsContainer)) &&
131 !IsRecursiveContainer<T>::value>::type>
132 static void PrintValue(const T& container, std::ostream* os) {
133 const size_t kMaxCount = 32; // The maximum number of elements to print.
136 for (auto&& elem : container) {
139 if (count == kMaxCount) { // Enough has been printed.
145 // We cannot call PrintTo(elem, os) here as PrintTo() doesn't
146 // handle `elem` being a native array.
147 internal::UniversalPrint(elem, os);
158 // Used to print a pointer that is neither a char pointer nor a member
159 // pointer, when the user doesn't define PrintTo() for it. (A member
160 // variable pointer or member function pointer doesn't really point to
161 // a location in the address space. Their representation is
162 // implementation-defined. Therefore they will be printed as raw
164 struct FunctionPointerPrinter {
165 template <typename T, typename = typename std::enable_if<
166 std::is_function<T>::value>::type>
167 static void PrintValue(T* p, ::std::ostream* os) {
171 // T is a function type, so '*os << p' doesn't do what we want
172 // (it just prints p as bool). We want to print p as a const
174 *os << reinterpret_cast<const void*>(p);
179 struct PointerPrinter {
180 template <typename T>
181 static void PrintValue(T* p, ::std::ostream* os) {
185 // T is not a function type. We just call << to print p,
186 // relying on ADL to pick up user-defined << for their pointer
193 namespace internal_stream_operator_without_lexical_name_lookup {
195 // The presence of an operator<< here will terminate lexical scope lookup
196 // straight away (even though it cannot be a match because of its argument
197 // types). Thus, the two operator<< calls in StreamPrinter will find only ADL
199 struct LookupBlocker {};
200 void operator<<(LookupBlocker, LookupBlocker);
202 struct StreamPrinter {
203 template <typename T,
204 // Don't accept member pointers here. We'd print them via implicit
205 // conversion to bool, which isn't useful.
206 typename = typename std::enable_if<
207 !std::is_member_pointer<T>::value>::type,
208 // Only accept types for which we can find a streaming operator via
209 // ADL (possibly involving implicit conversions).
210 typename = decltype(std::declval<std::ostream&>()
211 << std::declval<const T&>())>
212 static void PrintValue(const T& value, ::std::ostream* os) {
213 // Call streaming operator found by ADL, possibly with implicit conversions
219 } // namespace internal_stream_operator_without_lexical_name_lookup
221 struct ProtobufPrinter {
222 // We print a protobuf using its ShortDebugString() when the string
223 // doesn't exceed this many characters; otherwise we print it using
224 // DebugString() for better readability.
225 static const size_t kProtobufOneLinerMaxLength = 50;
227 template <typename T,
228 typename = typename std::enable_if<
229 internal::HasDebugStringAndShortDebugString<T>::value>::type>
230 static void PrintValue(const T& value, ::std::ostream* os) {
231 std::string pretty_str = value.ShortDebugString();
232 if (pretty_str.length() > kProtobufOneLinerMaxLength) {
233 pretty_str = "\n" + value.DebugString();
235 *os << ("<" + pretty_str + ">");
239 struct ConvertibleToIntegerPrinter {
240 // Since T has no << operator or PrintTo() but can be implicitly
241 // converted to BiggestInt, we print it as a BiggestInt.
243 // Most likely T is an enum type (either named or unnamed), in which
244 // case printing it as an integer is the desired behavior. In case
245 // T is not an enum, printing it as an integer is the best we can do
246 // given that it has no user-defined printer.
247 static void PrintValue(internal::BiggestInt value, ::std::ostream* os) {
252 struct ConvertibleToStringViewPrinter {
253 #if GTEST_INTERNAL_HAS_STRING_VIEW
254 static void PrintValue(internal::StringView value, ::std::ostream* os) {
255 internal::UniversalPrint(value, os);
261 // Prints the given number of bytes in the given object to the given
263 GTEST_API_ void PrintBytesInObjectTo(const unsigned char* obj_bytes,
266 struct RawBytesPrinter {
267 // SFINAE on `sizeof` to make sure we have a complete type.
268 template <typename T, size_t = sizeof(T)>
269 static void PrintValue(const T& value, ::std::ostream* os) {
270 PrintBytesInObjectTo(
271 static_cast<const unsigned char*>(
272 // Load bearing cast to void* to support iOS
273 reinterpret_cast<const void*>(std::addressof(value))),
278 struct FallbackPrinter {
279 template <typename T>
280 static void PrintValue(const T&, ::std::ostream* os) {
281 *os << "(incomplete type)";
285 // Try every printer in order and return the first one that works.
286 template <typename T, typename E, typename Printer, typename... Printers>
287 struct FindFirstPrinter : FindFirstPrinter<T, E, Printers...> {};
289 template <typename T, typename Printer, typename... Printers>
290 struct FindFirstPrinter<
291 T, decltype(Printer::PrintValue(std::declval<const T&>(), nullptr)),
292 Printer, Printers...> {
293 using type = Printer;
296 // Select the best printer in the following order:
297 // - Print containers (they have begin/end/etc).
298 // - Print function pointers.
299 // - Print object pointers.
300 // - Use the stream operator, if available.
301 // - Print protocol buffers.
302 // - Print types convertible to BiggestInt.
303 // - Print types convertible to StringView, if available.
304 // - Fallback to printing the raw bytes of the object.
305 template <typename T>
306 void PrintWithFallback(const T& value, ::std::ostream* os) {
307 using Printer = typename FindFirstPrinter<
308 T, void, ContainerPrinter, FunctionPointerPrinter, PointerPrinter,
309 internal_stream_operator_without_lexical_name_lookup::StreamPrinter,
310 ProtobufPrinter, ConvertibleToIntegerPrinter,
311 ConvertibleToStringViewPrinter, RawBytesPrinter, FallbackPrinter>::type;
312 Printer::PrintValue(value, os);
315 // FormatForComparison<ToPrint, OtherOperand>::Format(value) formats a
316 // value of type ToPrint that is an operand of a comparison assertion
317 // (e.g. ASSERT_EQ). OtherOperand is the type of the other operand in
318 // the comparison, and is used to help determine the best way to
319 // format the value. In particular, when the value is a C string
320 // (char pointer) and the other operand is an STL string object, we
321 // want to format the C string as a string, since we know it is
322 // compared by value with the string object. If the value is a char
323 // pointer but the other operand is not an STL string object, we don't
324 // know whether the pointer is supposed to point to a NUL-terminated
325 // string, and thus want to print it as a pointer to be safe.
327 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
330 template <typename ToPrint, typename OtherOperand>
331 class FormatForComparison {
333 static ::std::string Format(const ToPrint& value) {
334 return ::testing::PrintToString(value);
339 template <typename ToPrint, size_t N, typename OtherOperand>
340 class FormatForComparison<ToPrint[N], OtherOperand> {
342 static ::std::string Format(const ToPrint* value) {
343 return FormatForComparison<const ToPrint*, OtherOperand>::Format(value);
347 // By default, print C string as pointers to be safe, as we don't know
348 // whether they actually point to a NUL-terminated string.
350 #define GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(CharType) \
351 template <typename OtherOperand> \
352 class FormatForComparison<CharType*, OtherOperand> { \
354 static ::std::string Format(CharType* value) { \
355 return ::testing::PrintToString(static_cast<const void*>(value)); \
359 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char);
360 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char);
361 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(wchar_t);
362 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const wchar_t);
364 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char8_t);
365 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char8_t);
367 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char16_t);
368 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char16_t);
369 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char32_t);
370 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char32_t);
372 #undef GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_
374 // If a C string is compared with an STL string object, we know it's meant
375 // to point to a NUL-terminated string, and thus can print it as a string.
377 #define GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(CharType, OtherStringType) \
379 class FormatForComparison<CharType*, OtherStringType> { \
381 static ::std::string Format(CharType* value) { \
382 return ::testing::PrintToString(value); \
386 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::std::string);
387 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::std::string);
389 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char8_t, ::std::u8string);
390 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char8_t, ::std::u8string);
392 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char16_t, ::std::u16string);
393 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char16_t, ::std::u16string);
394 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char32_t, ::std::u32string);
395 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char32_t, ::std::u32string);
397 #if GTEST_HAS_STD_WSTRING
398 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(wchar_t, ::std::wstring);
399 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const wchar_t, ::std::wstring);
402 #undef GTEST_IMPL_FORMAT_C_STRING_AS_STRING_
404 // Formats a comparison assertion (e.g. ASSERT_EQ, EXPECT_LT, and etc)
405 // operand to be used in a failure message. The type (but not value)
406 // of the other operand may affect the format. This allows us to
407 // print a char* as a raw pointer when it is compared against another
408 // char* or void*, and print it as a C string when it is compared
409 // against an std::string object, for example.
411 // INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
412 template <typename T1, typename T2>
413 std::string FormatForComparisonFailureMessage(
414 const T1& value, const T2& /* other_operand */) {
415 return FormatForComparison<T1, T2>::Format(value);
418 // UniversalPrinter<T>::Print(value, ostream_ptr) prints the given
419 // value to the given ostream. The caller must ensure that
420 // 'ostream_ptr' is not NULL, or the behavior is undefined.
422 // We define UniversalPrinter as a class template (as opposed to a
423 // function template), as we need to partially specialize it for
424 // reference types, which cannot be done with function templates.
425 template <typename T>
426 class UniversalPrinter;
428 // Prints the given value using the << operator if it has one;
429 // otherwise prints the bytes in it. This is what
430 // UniversalPrinter<T>::Print() does when PrintTo() is not specialized
431 // or overloaded for type T.
433 // A user can override this behavior for a class type Foo by defining
434 // an overload of PrintTo() in the namespace where Foo is defined. We
435 // give the user this option as sometimes defining a << operator for
436 // Foo is not desirable (e.g. the coding style may prevent doing it,
437 // or there is already a << operator but it doesn't do what the user
439 template <typename T>
440 void PrintTo(const T& value, ::std::ostream* os) {
441 internal::PrintWithFallback(value, os);
444 // The following list of PrintTo() overloads tells
445 // UniversalPrinter<T>::Print() how to print standard types (built-in
446 // types, strings, plain arrays, and pointers).
448 // Overloads for various char types.
449 GTEST_API_ void PrintTo(unsigned char c, ::std::ostream* os);
450 GTEST_API_ void PrintTo(signed char c, ::std::ostream* os);
451 inline void PrintTo(char c, ::std::ostream* os) {
452 // When printing a plain char, we always treat it as unsigned. This
453 // way, the output won't be affected by whether the compiler thinks
454 // char is signed or not.
455 PrintTo(static_cast<unsigned char>(c), os);
458 // Overloads for other simple built-in types.
459 inline void PrintTo(bool x, ::std::ostream* os) {
460 *os << (x ? "true" : "false");
463 // Overload for wchar_t type.
464 // Prints a wchar_t as a symbol if it is printable or as its internal
465 // code otherwise and also as its decimal code (except for L'\0').
466 // The L'\0' char is printed as "L'\\0'". The decimal code is printed
467 // as signed integer when wchar_t is implemented by the compiler
468 // as a signed type and is printed as an unsigned integer when wchar_t
469 // is implemented as an unsigned type.
470 GTEST_API_ void PrintTo(wchar_t wc, ::std::ostream* os);
472 GTEST_API_ void PrintTo(char32_t c, ::std::ostream* os);
473 inline void PrintTo(char16_t c, ::std::ostream* os) {
474 PrintTo(ImplicitCast_<char32_t>(c), os);
477 inline void PrintTo(char8_t c, ::std::ostream* os) {
478 PrintTo(ImplicitCast_<char32_t>(c), os);
482 // Overloads for C strings.
483 GTEST_API_ void PrintTo(const char* s, ::std::ostream* os);
484 inline void PrintTo(char* s, ::std::ostream* os) {
485 PrintTo(ImplicitCast_<const char*>(s), os);
488 // signed/unsigned char is often used for representing binary data, so
489 // we print pointers to it as void* to be safe.
490 inline void PrintTo(const signed char* s, ::std::ostream* os) {
491 PrintTo(ImplicitCast_<const void*>(s), os);
493 inline void PrintTo(signed char* s, ::std::ostream* os) {
494 PrintTo(ImplicitCast_<const void*>(s), os);
496 inline void PrintTo(const unsigned char* s, ::std::ostream* os) {
497 PrintTo(ImplicitCast_<const void*>(s), os);
499 inline void PrintTo(unsigned char* s, ::std::ostream* os) {
500 PrintTo(ImplicitCast_<const void*>(s), os);
503 // Overloads for u8 strings.
504 GTEST_API_ void PrintTo(const char8_t* s, ::std::ostream* os);
505 inline void PrintTo(char8_t* s, ::std::ostream* os) {
506 PrintTo(ImplicitCast_<const char8_t*>(s), os);
509 // Overloads for u16 strings.
510 GTEST_API_ void PrintTo(const char16_t* s, ::std::ostream* os);
511 inline void PrintTo(char16_t* s, ::std::ostream* os) {
512 PrintTo(ImplicitCast_<const char16_t*>(s), os);
514 // Overloads for u32 strings.
515 GTEST_API_ void PrintTo(const char32_t* s, ::std::ostream* os);
516 inline void PrintTo(char32_t* s, ::std::ostream* os) {
517 PrintTo(ImplicitCast_<const char32_t*>(s), os);
520 // MSVC can be configured to define wchar_t as a typedef of unsigned
521 // short. It defines _NATIVE_WCHAR_T_DEFINED when wchar_t is a native
522 // type. When wchar_t is a typedef, defining an overload for const
523 // wchar_t* would cause unsigned short* be printed as a wide string,
524 // possibly causing invalid memory accesses.
525 #if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
526 // Overloads for wide C strings
527 GTEST_API_ void PrintTo(const wchar_t* s, ::std::ostream* os);
528 inline void PrintTo(wchar_t* s, ::std::ostream* os) {
529 PrintTo(ImplicitCast_<const wchar_t*>(s), os);
533 // Overload for C arrays. Multi-dimensional arrays are printed
536 // Prints the given number of elements in an array, without printing
538 template <typename T>
539 void PrintRawArrayTo(const T a[], size_t count, ::std::ostream* os) {
540 UniversalPrint(a[0], os);
541 for (size_t i = 1; i != count; i++) {
543 UniversalPrint(a[i], os);
547 // Overloads for ::std::string.
548 GTEST_API_ void PrintStringTo(const ::std::string&s, ::std::ostream* os);
549 inline void PrintTo(const ::std::string& s, ::std::ostream* os) {
550 PrintStringTo(s, os);
553 // Overloads for ::std::u8string
555 GTEST_API_ void PrintU8StringTo(const ::std::u8string& s, ::std::ostream* os);
556 inline void PrintTo(const ::std::u8string& s, ::std::ostream* os) {
557 PrintU8StringTo(s, os);
561 // Overloads for ::std::u16string
562 GTEST_API_ void PrintU16StringTo(const ::std::u16string& s, ::std::ostream* os);
563 inline void PrintTo(const ::std::u16string& s, ::std::ostream* os) {
564 PrintU16StringTo(s, os);
567 // Overloads for ::std::u32string
568 GTEST_API_ void PrintU32StringTo(const ::std::u32string& s, ::std::ostream* os);
569 inline void PrintTo(const ::std::u32string& s, ::std::ostream* os) {
570 PrintU32StringTo(s, os);
573 // Overloads for ::std::wstring.
574 #if GTEST_HAS_STD_WSTRING
575 GTEST_API_ void PrintWideStringTo(const ::std::wstring&s, ::std::ostream* os);
576 inline void PrintTo(const ::std::wstring& s, ::std::ostream* os) {
577 PrintWideStringTo(s, os);
579 #endif // GTEST_HAS_STD_WSTRING
581 #if GTEST_INTERNAL_HAS_STRING_VIEW
582 // Overload for internal::StringView.
583 inline void PrintTo(internal::StringView sp, ::std::ostream* os) {
584 PrintTo(::std::string(sp), os);
586 #endif // GTEST_INTERNAL_HAS_STRING_VIEW
588 inline void PrintTo(std::nullptr_t, ::std::ostream* os) { *os << "(nullptr)"; }
590 template <typename T>
591 void PrintTo(std::reference_wrapper<T> ref, ::std::ostream* os) {
592 UniversalPrinter<T&>::Print(ref.get(), os);
595 inline const void* VoidifyPointer(const void* p) { return p; }
596 inline const void* VoidifyPointer(volatile const void* p) {
597 return const_cast<const void*>(p);
600 template <typename T, typename Ptr>
601 void PrintSmartPointer(const Ptr& ptr, std::ostream* os, char) {
602 if (ptr == nullptr) {
605 // We can't print the value. Just print the pointer..
606 *os << "(" << (VoidifyPointer)(ptr.get()) << ")";
609 template <typename T, typename Ptr,
610 typename = typename std::enable_if<!std::is_void<T>::value &&
611 !std::is_array<T>::value>::type>
612 void PrintSmartPointer(const Ptr& ptr, std::ostream* os, int) {
613 if (ptr == nullptr) {
616 *os << "(ptr = " << (VoidifyPointer)(ptr.get()) << ", value = ";
617 UniversalPrinter<T>::Print(*ptr, os);
622 template <typename T, typename D>
623 void PrintTo(const std::unique_ptr<T, D>& ptr, std::ostream* os) {
624 (PrintSmartPointer<T>)(ptr, os, 0);
627 template <typename T>
628 void PrintTo(const std::shared_ptr<T>& ptr, std::ostream* os) {
629 (PrintSmartPointer<T>)(ptr, os, 0);
632 // Helper function for printing a tuple. T must be instantiated with
634 template <typename T>
635 void PrintTupleTo(const T&, std::integral_constant<size_t, 0>,
638 template <typename T, size_t I>
639 void PrintTupleTo(const T& t, std::integral_constant<size_t, I>,
640 ::std::ostream* os) {
641 PrintTupleTo(t, std::integral_constant<size_t, I - 1>(), os);
642 GTEST_INTENTIONAL_CONST_COND_PUSH_()
644 GTEST_INTENTIONAL_CONST_COND_POP_()
647 UniversalPrinter<typename std::tuple_element<I - 1, T>::type>::Print(
648 std::get<I - 1>(t), os);
651 template <typename... Types>
652 void PrintTo(const ::std::tuple<Types...>& t, ::std::ostream* os) {
654 PrintTupleTo(t, std::integral_constant<size_t, sizeof...(Types)>(), os);
658 // Overload for std::pair.
659 template <typename T1, typename T2>
660 void PrintTo(const ::std::pair<T1, T2>& value, ::std::ostream* os) {
662 // We cannot use UniversalPrint(value.first, os) here, as T1 may be
663 // a reference type. The same for printing value.second.
664 UniversalPrinter<T1>::Print(value.first, os);
666 UniversalPrinter<T2>::Print(value.second, os);
670 // Implements printing a non-reference type T by letting the compiler
671 // pick the right overload of PrintTo() for T.
672 template <typename T>
673 class UniversalPrinter {
675 // MSVC warns about adding const to a function type, so we want to
676 // disable the warning.
677 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
679 // Note: we deliberately don't call this PrintTo(), as that name
680 // conflicts with ::testing::internal::PrintTo in the body of the
682 static void Print(const T& value, ::std::ostream* os) {
683 // By default, ::testing::internal::PrintTo() is used for printing
686 // Thanks to Koenig look-up, if T is a class and has its own
687 // PrintTo() function defined in its namespace, that function will
688 // be visible here. Since it is more specific than the generic ones
689 // in ::testing::internal, it will be picked by the compiler in the
690 // following statement - exactly what we want.
694 GTEST_DISABLE_MSC_WARNINGS_POP_()
697 // Remove any const-qualifiers before passing a type to UniversalPrinter.
698 template <typename T>
699 class UniversalPrinter<const T> : public UniversalPrinter<T> {};
701 #if GTEST_INTERNAL_HAS_ANY
703 // Printer for std::any / absl::any
706 class UniversalPrinter<Any> {
708 static void Print(const Any& value, ::std::ostream* os) {
709 if (value.has_value()) {
710 *os << "value of type " << GetTypeName(value);
717 static std::string GetTypeName(const Any& value) {
719 return internal::GetTypeName(value.type());
721 static_cast<void>(value); // possibly unused
722 return "<unknown_type>";
723 #endif // GTEST_HAS_RTTI
727 #endif // GTEST_INTERNAL_HAS_ANY
729 #if GTEST_INTERNAL_HAS_OPTIONAL
731 // Printer for std::optional / absl::optional
733 template <typename T>
734 class UniversalPrinter<Optional<T>> {
736 static void Print(const Optional<T>& value, ::std::ostream* os) {
741 UniversalPrint(*value, os);
747 #endif // GTEST_INTERNAL_HAS_OPTIONAL
749 #if GTEST_INTERNAL_HAS_VARIANT
751 // Printer for std::variant / absl::variant
753 template <typename... T>
754 class UniversalPrinter<Variant<T...>> {
756 static void Print(const Variant<T...>& value, ::std::ostream* os) {
759 absl::visit(Visitor{os, value.index()}, value);
761 std::visit(Visitor{os, value.index()}, value);
762 #endif // GTEST_HAS_ABSL
768 template <typename U>
769 void operator()(const U& u) const {
770 *os << "'" << GetTypeName<U>() << "(index = " << index
772 UniversalPrint(u, os);
779 #endif // GTEST_INTERNAL_HAS_VARIANT
781 // UniversalPrintArray(begin, len, os) prints an array of 'len'
782 // elements, starting at address 'begin'.
783 template <typename T>
784 void UniversalPrintArray(const T* begin, size_t len, ::std::ostream* os) {
789 const size_t kThreshold = 18;
790 const size_t kChunkSize = 8;
791 // If the array has more than kThreshold elements, we'll have to
792 // omit some details by printing only the first and the last
793 // kChunkSize elements.
794 if (len <= kThreshold) {
795 PrintRawArrayTo(begin, len, os);
797 PrintRawArrayTo(begin, kChunkSize, os);
799 PrintRawArrayTo(begin + len - kChunkSize, kChunkSize, os);
804 // This overload prints a (const) char array compactly.
805 GTEST_API_ void UniversalPrintArray(
806 const char* begin, size_t len, ::std::ostream* os);
809 // This overload prints a (const) char8_t array compactly.
810 GTEST_API_ void UniversalPrintArray(const char8_t* begin, size_t len,
814 // This overload prints a (const) char16_t array compactly.
815 GTEST_API_ void UniversalPrintArray(const char16_t* begin, size_t len,
818 // This overload prints a (const) char32_t array compactly.
819 GTEST_API_ void UniversalPrintArray(const char32_t* begin, size_t len,
822 // This overload prints a (const) wchar_t array compactly.
823 GTEST_API_ void UniversalPrintArray(
824 const wchar_t* begin, size_t len, ::std::ostream* os);
826 // Implements printing an array type T[N].
827 template <typename T, size_t N>
828 class UniversalPrinter<T[N]> {
830 // Prints the given array, omitting some elements when there are too
832 static void Print(const T (&a)[N], ::std::ostream* os) {
833 UniversalPrintArray(a, N, os);
837 // Implements printing a reference type T&.
838 template <typename T>
839 class UniversalPrinter<T&> {
841 // MSVC warns about adding const to a function type, so we want to
842 // disable the warning.
843 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
845 static void Print(const T& value, ::std::ostream* os) {
846 // Prints the address of the value. We use reinterpret_cast here
847 // as static_cast doesn't compile when T is a function type.
848 *os << "@" << reinterpret_cast<const void*>(&value) << " ";
850 // Then prints the value itself.
851 UniversalPrint(value, os);
854 GTEST_DISABLE_MSC_WARNINGS_POP_()
857 // Prints a value tersely: for a reference type, the referenced value
858 // (but not the address) is printed; for a (const) char pointer, the
859 // NUL-terminated string (but not the pointer) is printed.
861 template <typename T>
862 class UniversalTersePrinter {
864 static void Print(const T& value, ::std::ostream* os) {
865 UniversalPrint(value, os);
868 template <typename T>
869 class UniversalTersePrinter<T&> {
871 static void Print(const T& value, ::std::ostream* os) {
872 UniversalPrint(value, os);
875 template <typename T, size_t N>
876 class UniversalTersePrinter<T[N]> {
878 static void Print(const T (&value)[N], ::std::ostream* os) {
879 UniversalPrinter<T[N]>::Print(value, os);
883 class UniversalTersePrinter<const char*> {
885 static void Print(const char* str, ::std::ostream* os) {
886 if (str == nullptr) {
889 UniversalPrint(std::string(str), os);
894 class UniversalTersePrinter<char*> : public UniversalTersePrinter<const char*> {
899 class UniversalTersePrinter<const char8_t*> {
901 static void Print(const char8_t* str, ::std::ostream* os) {
902 if (str == nullptr) {
905 UniversalPrint(::std::u8string(str), os);
910 class UniversalTersePrinter<char8_t*>
911 : public UniversalTersePrinter<const char8_t*> {};
915 class UniversalTersePrinter<const char16_t*> {
917 static void Print(const char16_t* str, ::std::ostream* os) {
918 if (str == nullptr) {
921 UniversalPrint(::std::u16string(str), os);
926 class UniversalTersePrinter<char16_t*>
927 : public UniversalTersePrinter<const char16_t*> {};
930 class UniversalTersePrinter<const char32_t*> {
932 static void Print(const char32_t* str, ::std::ostream* os) {
933 if (str == nullptr) {
936 UniversalPrint(::std::u32string(str), os);
941 class UniversalTersePrinter<char32_t*>
942 : public UniversalTersePrinter<const char32_t*> {};
944 #if GTEST_HAS_STD_WSTRING
946 class UniversalTersePrinter<const wchar_t*> {
948 static void Print(const wchar_t* str, ::std::ostream* os) {
949 if (str == nullptr) {
952 UniversalPrint(::std::wstring(str), os);
959 class UniversalTersePrinter<wchar_t*> {
961 static void Print(wchar_t* str, ::std::ostream* os) {
962 UniversalTersePrinter<const wchar_t*>::Print(str, os);
966 template <typename T>
967 void UniversalTersePrint(const T& value, ::std::ostream* os) {
968 UniversalTersePrinter<T>::Print(value, os);
971 // Prints a value using the type inferred by the compiler. The
972 // difference between this and UniversalTersePrint() is that for a
973 // (const) char pointer, this prints both the pointer and the
974 // NUL-terminated string.
975 template <typename T>
976 void UniversalPrint(const T& value, ::std::ostream* os) {
977 // A workarond for the bug in VC++ 7.1 that prevents us from instantiating
978 // UniversalPrinter with T directly.
980 UniversalPrinter<T1>::Print(value, os);
983 typedef ::std::vector< ::std::string> Strings;
985 // Tersely prints the first N fields of a tuple to a string vector,
986 // one element for each field.
987 template <typename Tuple>
988 void TersePrintPrefixToStrings(const Tuple&, std::integral_constant<size_t, 0>,
990 template <typename Tuple, size_t I>
991 void TersePrintPrefixToStrings(const Tuple& t,
992 std::integral_constant<size_t, I>,
994 TersePrintPrefixToStrings(t, std::integral_constant<size_t, I - 1>(),
996 ::std::stringstream ss;
997 UniversalTersePrint(std::get<I - 1>(t), &ss);
998 strings->push_back(ss.str());
1001 // Prints the fields of a tuple tersely to a string vector, one
1002 // element for each field. See the comment before
1003 // UniversalTersePrint() for how we define "tersely".
1004 template <typename Tuple>
1005 Strings UniversalTersePrintTupleFieldsToStrings(const Tuple& value) {
1007 TersePrintPrefixToStrings(
1008 value, std::integral_constant<size_t, std::tuple_size<Tuple>::value>(),
1013 } // namespace internal
1015 template <typename T>
1016 ::std::string PrintToString(const T& value) {
1017 ::std::stringstream ss;
1018 internal::UniversalTersePrinter<T>::Print(value, &ss);
1022 } // namespace testing
1024 // Include any custom printer added by the local installation.
1025 // We must include this header at the end to make sure it can use the
1026 // declarations from this file.
1027 #include "gtest/internal/custom/gtest-printers.h"
1029 #endif // GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_