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17//
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27// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30
31// Google Test - The Google C++ Testing and Mocking Framework
32//
33// This file implements a universal value printer that can print a
34// value of any type T:
35//
36// void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
37//
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
42// foo):
43//
44// 1. foo::PrintTo(const T&, ostream*)
45// 2. operator<<(ostream&, const T&) defined in either foo or the
46// global namespace.
47//
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.
51//
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
54// value otherwise.
55//
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
59// printed.
60//
61// We also provide some convenient wrappers:
62//
63// // Prints a value to a string. For a (const or not) char
64// // pointer, the NUL-terminated string (but not the pointer) is
65// // printed.
66// std::string ::testing::PrintToString(const T& value);
67//
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
71// // printed.
72// void ::testing::internal::UniversalTersePrint(const T& value, ostream*);
73//
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*);
78//
79// // Prints the fields of a tuple tersely to a string vector, one
80// // element for each field. Tuple support must be enabled in
81// // gtest-port.h.
82// std::vector<string> UniversalTersePrintTupleFieldsToStrings(
83// const Tuple& value);
84//
85// Known limitation:
86//
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
96// value_type.
97
98// GOOGLETEST_CM0001 DO NOT DELETE
99
100#ifndef GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
101#define GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
102
103#include <functional>
104#include <ostream> // NOLINT
105#include <sstream>
106#include <string>
107#include <tuple>
108#include <type_traits>
109#include <utility>
110#include <vector>
111#include "gtest/internal/gtest-internal.h"
112#include "gtest/internal/gtest-port.h"
113
114namespace testing {
115
116// Definitions in the internal* namespaces are subject to change without notice.
117// DO NOT USE THEM IN USER CODE!
118namespace internal {
119
120template <typename T>
121void UniversalPrint(const T& value, ::std::ostream* os);
122
123// Used to print an STL-style container when the user doesn't define
124// a PrintTo() for it.
125struct ContainerPrinter {
126 template <typename T,
127 typename = typename std::enable_if<
128 (sizeof(IsContainerTest<T>(0)) == sizeof(IsContainer)) &&
129 !IsRecursiveContainer<T>::value>::type>
130 static void PrintValue(const T& container, std::ostream* os) {
131 const size_t kMaxCount = 32; // The maximum number of elements to print.
132 *os << '{';
133 size_t count = 0;
134 for (auto&& elem : container) {
135 if (count > 0) {
136 *os << ',';
137 if (count == kMaxCount) { // Enough has been printed.
138 *os << " ...";
139 break;
140 }
141 }
142 *os << ' ';
143 // We cannot call PrintTo(elem, os) here as PrintTo() doesn't
144 // handle `elem` being a native array.
145 internal::UniversalPrint(elem, os);
146 ++count;
147 }
148
149 if (count > 0) {
150 *os << ' ';
151 }
152 *os << '}';
153 }
154};
155
156// Used to print a pointer that is neither a char pointer nor a member
157// pointer, when the user doesn't define PrintTo() for it. (A member
158// variable pointer or member function pointer doesn't really point to
159// a location in the address space. Their representation is
160// implementation-defined. Therefore they will be printed as raw
161// bytes.)
162struct FunctionPointerPrinter {
163 template <typename T, typename = typename std::enable_if<
164 std::is_function<T>::value>::type>
165 static void PrintValue(T* p, ::std::ostream* os) {
166 if (p == nullptr) {
167 *os << "NULL";
168 } else {
169 // T is a function type, so '*os << p' doesn't do what we want
170 // (it just prints p as bool). We want to print p as a const
171 // void*.
172 *os << reinterpret_cast<const void*>(p);
173 }
174 }
175};
176
177struct PointerPrinter {
178 template <typename T>
179 static void PrintValue(T* p, ::std::ostream* os) {
180 if (p == nullptr) {
181 *os << "NULL";
182 } else {
183 // T is not a function type. We just call << to print p,
184 // relying on ADL to pick up user-defined << for their pointer
185 // types, if any.
186 *os << p;
187 }
188 }
189};
190
191namespace internal_stream_operator_without_lexical_name_lookup {
192
193// The presence of an operator<< here will terminate lexical scope lookup
194// straight away (even though it cannot be a match because of its argument
195// types). Thus, the two operator<< calls in StreamPrinter will find only ADL
196// candidates.
197struct LookupBlocker {};
198void operator<<(LookupBlocker, LookupBlocker);
199
200struct StreamPrinter {
201 template <typename T,
202 // Don't accept member pointers here. We'd print them via implicit
203 // conversion to bool, which isn't useful.
204 typename = typename std::enable_if<
205 !std::is_member_pointer<T>::value>::type,
206 // Only accept types for which we can find a streaming operator via
207 // ADL (possibly involving implicit conversions).
208 typename = decltype(std::declval<std::ostream&>()
209 << std::declval<const T&>())>
210 static void PrintValue(const T& value, ::std::ostream* os) {
211 // Call streaming operator found by ADL, possibly with implicit conversions
212 // of the arguments.
213 *os << value;
214 }
215};
216
217} // namespace internal_stream_operator_without_lexical_name_lookup
218
219struct ProtobufPrinter {
220 // We print a protobuf using its ShortDebugString() when the string
221 // doesn't exceed this many characters; otherwise we print it using
222 // DebugString() for better readability.
223 static const size_t kProtobufOneLinerMaxLength = 50;
224
225 template <typename T,
226 typename = typename std::enable_if<
227 internal::HasDebugStringAndShortDebugString<T>::value>::type>
228 static void PrintValue(const T& value, ::std::ostream* os) {
229 std::string pretty_str = value.ShortDebugString();
230 if (pretty_str.length() > kProtobufOneLinerMaxLength) {
231 pretty_str = "\n" + value.DebugString();
232 }
233 *os << ("<" + pretty_str + ">");
234 }
235};
236
237struct ConvertibleToIntegerPrinter {
238 // Since T has no << operator or PrintTo() but can be implicitly
239 // converted to BiggestInt, we print it as a BiggestInt.
240 //
241 // Most likely T is an enum type (either named or unnamed), in which
242 // case printing it as an integer is the desired behavior. In case
243 // T is not an enum, printing it as an integer is the best we can do
244 // given that it has no user-defined printer.
245 static void PrintValue(internal::BiggestInt value, ::std::ostream* os) {
246 *os << value;
247 }
248};
249
250struct ConvertibleToStringViewPrinter {
251#if GTEST_INTERNAL_HAS_STRING_VIEW
252 static void PrintValue(internal::StringView value, ::std::ostream* os) {
253 internal::UniversalPrint(value, os);
254 }
255#endif
256};
257
258
259// Prints the given number of bytes in the given object to the given
260// ostream.
261GTEST_API_ void PrintBytesInObjectTo(const unsigned char* obj_bytes,
262 size_t count,
263 ::std::ostream* os);
264struct FallbackPrinter {
265 template <typename T>
266 static void PrintValue(const T& value, ::std::ostream* os) {
267 PrintBytesInObjectTo(
268 static_cast<const unsigned char*>(
269 reinterpret_cast<const void*>(std::addressof(value))),
270 sizeof(value), os);
271 }
272};
273
274// Try every printer in order and return the first one that works.
275template <typename T, typename E, typename Printer, typename... Printers>
276struct FindFirstPrinter : FindFirstPrinter<T, E, Printers...> {};
277
278template <typename T, typename Printer, typename... Printers>
279struct FindFirstPrinter<
280 T, decltype(Printer::PrintValue(std::declval<const T&>(), nullptr)),
281 Printer, Printers...> {
282 using type = Printer;
283};
284
285// Select the best printer in the following order:
286// - Print containers (they have begin/end/etc).
287// - Print function pointers.
288// - Print object pointers.
289// - Use the stream operator, if available.
290// - Print protocol buffers.
291// - Print types convertible to BiggestInt.
292// - Print types convertible to StringView, if available.
293// - Fallback to printing the raw bytes of the object.
294template <typename T>
295void PrintWithFallback(const T& value, ::std::ostream* os) {
296 using Printer = typename FindFirstPrinter<
297 T, void, ContainerPrinter, FunctionPointerPrinter, PointerPrinter,
298 internal_stream_operator_without_lexical_name_lookup::StreamPrinter,
299 ProtobufPrinter, ConvertibleToIntegerPrinter,
300 ConvertibleToStringViewPrinter, FallbackPrinter>::type;
301 Printer::PrintValue(value, os);
302}
303
304// FormatForComparison<ToPrint, OtherOperand>::Format(value) formats a
305// value of type ToPrint that is an operand of a comparison assertion
306// (e.g. ASSERT_EQ). OtherOperand is the type of the other operand in
307// the comparison, and is used to help determine the best way to
308// format the value. In particular, when the value is a C string
309// (char pointer) and the other operand is an STL string object, we
310// want to format the C string as a string, since we know it is
311// compared by value with the string object. If the value is a char
312// pointer but the other operand is not an STL string object, we don't
313// know whether the pointer is supposed to point to a NUL-terminated
314// string, and thus want to print it as a pointer to be safe.
315//
316// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
317
318// The default case.
319template <typename ToPrint, typename OtherOperand>
320class FormatForComparison {
321 public:
322 static ::std::string Format(const ToPrint& value) {
323 return ::testing::PrintToString(value);
324 }
325};
326
327// Array.
328template <typename ToPrint, size_t N, typename OtherOperand>
329class FormatForComparison<ToPrint[N], OtherOperand> {
330 public:
331 static ::std::string Format(const ToPrint* value) {
332 return FormatForComparison<const ToPrint*, OtherOperand>::Format(value);
333 }
334};
335
336// By default, print C string as pointers to be safe, as we don't know
337// whether they actually point to a NUL-terminated string.
338
339#define GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(CharType) \
340 template <typename OtherOperand> \
341 class FormatForComparison<CharType*, OtherOperand> { \
342 public: \
343 static ::std::string Format(CharType* value) { \
344 return ::testing::PrintToString(static_cast<const void*>(value)); \
345 } \
346 }
347
348GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char);
349GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char);
350GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(wchar_t);
351GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const wchar_t);
352#ifdef __cpp_char8_t
353GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char8_t);
354GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char8_t);
355#endif
356GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char16_t);
357GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char16_t);
358GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char32_t);
359GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char32_t);
360
361#undef GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_
362
363// If a C string is compared with an STL string object, we know it's meant
364// to point to a NUL-terminated string, and thus can print it as a string.
365
366#define GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(CharType, OtherStringType) \
367 template <> \
368 class FormatForComparison<CharType*, OtherStringType> { \
369 public: \
370 static ::std::string Format(CharType* value) { \
371 return ::testing::PrintToString(value); \
372 } \
373 }
374
375GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::std::string);
376GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::std::string);
377#ifdef __cpp_char8_t
378GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char8_t, ::std::u8string);
379GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char8_t, ::std::u8string);
380#endif
381GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char16_t, ::std::u16string);
382GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char16_t, ::std::u16string);
383GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char32_t, ::std::u32string);
384GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char32_t, ::std::u32string);
385
386#if GTEST_HAS_STD_WSTRING
387GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(wchar_t, ::std::wstring);
388GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const wchar_t, ::std::wstring);
389#endif
390
391#undef GTEST_IMPL_FORMAT_C_STRING_AS_STRING_
392
393// Formats a comparison assertion (e.g. ASSERT_EQ, EXPECT_LT, and etc)
394// operand to be used in a failure message. The type (but not value)
395// of the other operand may affect the format. This allows us to
396// print a char* as a raw pointer when it is compared against another
397// char* or void*, and print it as a C string when it is compared
398// against an std::string object, for example.
399//
400// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
401template <typename T1, typename T2>
402std::string FormatForComparisonFailureMessage(
403 const T1& value, const T2& /* other_operand */) {
404 return FormatForComparison<T1, T2>::Format(value);
405}
406
407// UniversalPrinter<T>::Print(value, ostream_ptr) prints the given
408// value to the given ostream. The caller must ensure that
409// 'ostream_ptr' is not NULL, or the behavior is undefined.
410//
411// We define UniversalPrinter as a class template (as opposed to a
412// function template), as we need to partially specialize it for
413// reference types, which cannot be done with function templates.
414template <typename T>
415class UniversalPrinter;
416
417// Prints the given value using the << operator if it has one;
418// otherwise prints the bytes in it. This is what
419// UniversalPrinter<T>::Print() does when PrintTo() is not specialized
420// or overloaded for type T.
421//
422// A user can override this behavior for a class type Foo by defining
423// an overload of PrintTo() in the namespace where Foo is defined. We
424// give the user this option as sometimes defining a << operator for
425// Foo is not desirable (e.g. the coding style may prevent doing it,
426// or there is already a << operator but it doesn't do what the user
427// wants).
428template <typename T>
429void PrintTo(const T& value, ::std::ostream* os) {
430 internal::PrintWithFallback(value, os);
431}
432
433// The following list of PrintTo() overloads tells
434// UniversalPrinter<T>::Print() how to print standard types (built-in
435// types, strings, plain arrays, and pointers).
436
437// Overloads for various char types.
438GTEST_API_ void PrintTo(unsigned char c, ::std::ostream* os);
439GTEST_API_ void PrintTo(signed char c, ::std::ostream* os);
440inline void PrintTo(char c, ::std::ostream* os) {
441 // When printing a plain char, we always treat it as unsigned. This
442 // way, the output won't be affected by whether the compiler thinks
443 // char is signed or not.
444 PrintTo(static_cast<unsigned char>(c), os);
445}
446
447// Overloads for other simple built-in types.
448inline void PrintTo(bool x, ::std::ostream* os) {
449 *os << (x ? "true" : "false");
450}
451
452// Overload for wchar_t type.
453// Prints a wchar_t as a symbol if it is printable or as its internal
454// code otherwise and also as its decimal code (except for L'\0').
455// The L'\0' char is printed as "L'\\0'". The decimal code is printed
456// as signed integer when wchar_t is implemented by the compiler
457// as a signed type and is printed as an unsigned integer when wchar_t
458// is implemented as an unsigned type.
459GTEST_API_ void PrintTo(wchar_t wc, ::std::ostream* os);
460
461GTEST_API_ void PrintTo(char32_t c, ::std::ostream* os);
462inline void PrintTo(char16_t c, ::std::ostream* os) {
463 PrintTo(ImplicitCast_<char32_t>(c), os);
464}
465#ifdef __cpp_char8_t
466inline void PrintTo(char8_t c, ::std::ostream* os) {
467 PrintTo(ImplicitCast_<char32_t>(c), os);
468}
469#endif
470
471// Overloads for C strings.
472GTEST_API_ void PrintTo(const char* s, ::std::ostream* os);
473inline void PrintTo(char* s, ::std::ostream* os) {
474 PrintTo(ImplicitCast_<const char*>(s), os);
475}
476
477// signed/unsigned char is often used for representing binary data, so
478// we print pointers to it as void* to be safe.
479inline void PrintTo(const signed char* s, ::std::ostream* os) {
480 PrintTo(ImplicitCast_<const void*>(s), os);
481}
482inline void PrintTo(signed char* s, ::std::ostream* os) {
483 PrintTo(ImplicitCast_<const void*>(s), os);
484}
485inline void PrintTo(const unsigned char* s, ::std::ostream* os) {
486 PrintTo(ImplicitCast_<const void*>(s), os);
487}
488inline void PrintTo(unsigned char* s, ::std::ostream* os) {
489 PrintTo(ImplicitCast_<const void*>(s), os);
490}
491#ifdef __cpp_char8_t
492inline void PrintTo(const char8_t* s, ::std::ostream* os) {
493 PrintTo(ImplicitCast_<const void*>(s), os);
494}
495inline void PrintTo(char8_t* s, ::std::ostream* os) {
496 PrintTo(ImplicitCast_<const void*>(s), os);
497}
498#endif
499inline void PrintTo(const char16_t* s, ::std::ostream* os) {
500 PrintTo(ImplicitCast_<const void*>(s), os);
501}
502inline void PrintTo(char16_t* s, ::std::ostream* os) {
503 PrintTo(ImplicitCast_<const void*>(s), os);
504}
505inline void PrintTo(const char32_t* s, ::std::ostream* os) {
506 PrintTo(ImplicitCast_<const void*>(s), os);
507}
508inline void PrintTo(char32_t* s, ::std::ostream* os) {
509 PrintTo(ImplicitCast_<const void*>(s), os);
510}
511
512// MSVC can be configured to define wchar_t as a typedef of unsigned
513// short. It defines _NATIVE_WCHAR_T_DEFINED when wchar_t is a native
514// type. When wchar_t is a typedef, defining an overload for const
515// wchar_t* would cause unsigned short* be printed as a wide string,
516// possibly causing invalid memory accesses.
517#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
518// Overloads for wide C strings
519GTEST_API_ void PrintTo(const wchar_t* s, ::std::ostream* os);
520inline void PrintTo(wchar_t* s, ::std::ostream* os) {
521 PrintTo(ImplicitCast_<const wchar_t*>(s), os);
522}
523#endif
524
525// Overload for C arrays. Multi-dimensional arrays are printed
526// properly.
527
528// Prints the given number of elements in an array, without printing
529// the curly braces.
530template <typename T>
531void PrintRawArrayTo(const T a[], size_t count, ::std::ostream* os) {
532 UniversalPrint(a[0], os);
533 for (size_t i = 1; i != count; i++) {
534 *os << ", ";
535 UniversalPrint(a[i], os);
536 }
537}
538
539// Overloads for ::std::string.
540GTEST_API_ void PrintStringTo(const ::std::string&s, ::std::ostream* os);
541inline void PrintTo(const ::std::string& s, ::std::ostream* os) {
542 PrintStringTo(s, os);
543}
544
545// Overloads for ::std::wstring.
546#if GTEST_HAS_STD_WSTRING
547GTEST_API_ void PrintWideStringTo(const ::std::wstring&s, ::std::ostream* os);
548inline void PrintTo(const ::std::wstring& s, ::std::ostream* os) {
549 PrintWideStringTo(s, os);
550}
551#endif // GTEST_HAS_STD_WSTRING
552
553#if GTEST_INTERNAL_HAS_STRING_VIEW
554// Overload for internal::StringView.
555inline void PrintTo(internal::StringView sp, ::std::ostream* os) {
556 PrintTo(::std::string(sp), os);
557}
558#endif // GTEST_INTERNAL_HAS_STRING_VIEW
559
560inline void PrintTo(std::nullptr_t, ::std::ostream* os) { *os << "(nullptr)"; }
561
562template <typename T>
563void PrintTo(std::reference_wrapper<T> ref, ::std::ostream* os) {
564 UniversalPrinter<T&>::Print(ref.get(), os);
565}
566
567// Helper function for printing a tuple. T must be instantiated with
568// a tuple type.
569template <typename T>
570void PrintTupleTo(const T&, std::integral_constant<size_t, 0>,
571 ::std::ostream*) {}
572
573template <typename T, size_t I>
574void PrintTupleTo(const T& t, std::integral_constant<size_t, I>,
575 ::std::ostream* os) {
576 PrintTupleTo(t, std::integral_constant<size_t, I - 1>(), os);
577 GTEST_INTENTIONAL_CONST_COND_PUSH_()
578 if (I > 1) {
579 GTEST_INTENTIONAL_CONST_COND_POP_()
580 *os << ", ";
581 }
582 UniversalPrinter<typename std::tuple_element<I - 1, T>::type>::Print(
583 std::get<I - 1>(t), os);
584}
585
586template <typename... Types>
587void PrintTo(const ::std::tuple<Types...>& t, ::std::ostream* os) {
588 *os << "(";
589 PrintTupleTo(t, std::integral_constant<size_t, sizeof...(Types)>(), os);
590 *os << ")";
591}
592
593// Overload for std::pair.
594template <typename T1, typename T2>
595void PrintTo(const ::std::pair<T1, T2>& value, ::std::ostream* os) {
596 *os << '(';
597 // We cannot use UniversalPrint(value.first, os) here, as T1 may be
598 // a reference type. The same for printing value.second.
599 UniversalPrinter<T1>::Print(value.first, os);
600 *os << ", ";
601 UniversalPrinter<T2>::Print(value.second, os);
602 *os << ')';
603}
604
605// Implements printing a non-reference type T by letting the compiler
606// pick the right overload of PrintTo() for T.
607template <typename T>
608class UniversalPrinter {
609 public:
610 // MSVC warns about adding const to a function type, so we want to
611 // disable the warning.
612 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
613
614 // Note: we deliberately don't call this PrintTo(), as that name
615 // conflicts with ::testing::internal::PrintTo in the body of the
616 // function.
617 static void Print(const T& value, ::std::ostream* os) {
618 // By default, ::testing::internal::PrintTo() is used for printing
619 // the value.
620 //
621 // Thanks to Koenig look-up, if T is a class and has its own
622 // PrintTo() function defined in its namespace, that function will
623 // be visible here. Since it is more specific than the generic ones
624 // in ::testing::internal, it will be picked by the compiler in the
625 // following statement - exactly what we want.
626 PrintTo(value, os);
627 }
628
629 GTEST_DISABLE_MSC_WARNINGS_POP_()
630};
631
632#if GTEST_INTERNAL_HAS_ANY
633
634// Printer for std::any / absl::any
635
636template <>
637class UniversalPrinter<Any> {
638 public:
639 static void Print(const Any& value, ::std::ostream* os) {
640 if (value.has_value()) {
641 *os << "value of type " << GetTypeName(value);
642 } else {
643 *os << "no value";
644 }
645 }
646
647 private:
648 static std::string GetTypeName(const Any& value) {
649#if GTEST_HAS_RTTI
650 return internal::GetTypeName(value.type());
651#else
652 static_cast<void>(value); // possibly unused
653 return "<unknown_type>";
654#endif // GTEST_HAS_RTTI
655 }
656};
657
658#endif // GTEST_INTERNAL_HAS_ANY
659
660#if GTEST_INTERNAL_HAS_OPTIONAL
661
662// Printer for std::optional / absl::optional
663
664template <typename T>
665class UniversalPrinter<Optional<T>> {
666 public:
667 static void Print(const Optional<T>& value, ::std::ostream* os) {
668 *os << '(';
669 if (!value) {
670 *os << "nullopt";
671 } else {
672 UniversalPrint(*value, os);
673 }
674 *os << ')';
675 }
676};
677
678#endif // GTEST_INTERNAL_HAS_OPTIONAL
679
680#if GTEST_INTERNAL_HAS_VARIANT
681
682// Printer for std::variant / absl::variant
683
684template <typename... T>
685class UniversalPrinter<Variant<T...>> {
686 public:
687 static void Print(const Variant<T...>& value, ::std::ostream* os) {
688 *os << '(';
689#if GTEST_HAS_ABSL
690 absl::visit(Visitor{os, value.index()}, value);
691#else
692 std::visit(Visitor{os, value.index()}, value);
693#endif // GTEST_HAS_ABSL
694 *os << ')';
695 }
696
697 private:
698 struct Visitor {
699 template <typename U>
700 void operator()(const U& u) const {
701 *os << "'" << GetTypeName<U>() << "(index = " << index
702 << ")' with value ";
703 UniversalPrint(u, os);
704 }
705 ::std::ostream* os;
706 std::size_t index;
707 };
708};
709
710#endif // GTEST_INTERNAL_HAS_VARIANT
711
712// UniversalPrintArray(begin, len, os) prints an array of 'len'
713// elements, starting at address 'begin'.
714template <typename T>
715void UniversalPrintArray(const T* begin, size_t len, ::std::ostream* os) {
716 if (len == 0) {
717 *os << "{}";
718 } else {
719 *os << "{ ";
720 const size_t kThreshold = 18;
721 const size_t kChunkSize = 8;
722 // If the array has more than kThreshold elements, we'll have to
723 // omit some details by printing only the first and the last
724 // kChunkSize elements.
725 if (len <= kThreshold) {
726 PrintRawArrayTo(begin, len, os);
727 } else {
728 PrintRawArrayTo(begin, kChunkSize, os);
729 *os << ", ..., ";
730 PrintRawArrayTo(begin + len - kChunkSize, kChunkSize, os);
731 }
732 *os << " }";
733 }
734}
735// This overload prints a (const) char array compactly.
736GTEST_API_ void UniversalPrintArray(
737 const char* begin, size_t len, ::std::ostream* os);
738
739// This overload prints a (const) wchar_t array compactly.
740GTEST_API_ void UniversalPrintArray(
741 const wchar_t* begin, size_t len, ::std::ostream* os);
742
743// Implements printing an array type T[N].
744template <typename T, size_t N>
745class UniversalPrinter<T[N]> {
746 public:
747 // Prints the given array, omitting some elements when there are too
748 // many.
749 static void Print(const T (&a)[N], ::std::ostream* os) {
750 UniversalPrintArray(a, N, os);
751 }
752};
753
754// Implements printing a reference type T&.
755template <typename T>
756class UniversalPrinter<T&> {
757 public:
758 // MSVC warns about adding const to a function type, so we want to
759 // disable the warning.
760 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
761
762 static void Print(const T& value, ::std::ostream* os) {
763 // Prints the address of the value. We use reinterpret_cast here
764 // as static_cast doesn't compile when T is a function type.
765 *os << "@" << reinterpret_cast<const void*>(&value) << " ";
766
767 // Then prints the value itself.
768 UniversalPrint(value, os);
769 }
770
771 GTEST_DISABLE_MSC_WARNINGS_POP_()
772};
773
774// Prints a value tersely: for a reference type, the referenced value
775// (but not the address) is printed; for a (const) char pointer, the
776// NUL-terminated string (but not the pointer) is printed.
777
778template <typename T>
779class UniversalTersePrinter {
780 public:
781 static void Print(const T& value, ::std::ostream* os) {
782 UniversalPrint(value, os);
783 }
784};
785template <typename T>
786class UniversalTersePrinter<T&> {
787 public:
788 static void Print(const T& value, ::std::ostream* os) {
789 UniversalPrint(value, os);
790 }
791};
792template <typename T, size_t N>
793class UniversalTersePrinter<T[N]> {
794 public:
795 static void Print(const T (&value)[N], ::std::ostream* os) {
796 UniversalPrinter<T[N]>::Print(value, os);
797 }
798};
799template <>
800class UniversalTersePrinter<const char*> {
801 public:
802 static void Print(const char* str, ::std::ostream* os) {
803 if (str == nullptr) {
804 *os << "NULL";
805 } else {
806 UniversalPrint(std::string(str), os);
807 }
808 }
809};
810template <>
811class UniversalTersePrinter<char*> {
812 public:
813 static void Print(char* str, ::std::ostream* os) {
814 UniversalTersePrinter<const char*>::Print(str, os);
815 }
816};
817
818#if GTEST_HAS_STD_WSTRING
819template <>
820class UniversalTersePrinter<const wchar_t*> {
821 public:
822 static void Print(const wchar_t* str, ::std::ostream* os) {
823 if (str == nullptr) {
824 *os << "NULL";
825 } else {
826 UniversalPrint(::std::wstring(str), os);
827 }
828 }
829};
830#endif
831
832template <>
833class UniversalTersePrinter<wchar_t*> {
834 public:
835 static void Print(wchar_t* str, ::std::ostream* os) {
836 UniversalTersePrinter<const wchar_t*>::Print(str, os);
837 }
838};
839
840template <typename T>
841void UniversalTersePrint(const T& value, ::std::ostream* os) {
842 UniversalTersePrinter<T>::Print(value, os);
843}
844
845// Prints a value using the type inferred by the compiler. The
846// difference between this and UniversalTersePrint() is that for a
847// (const) char pointer, this prints both the pointer and the
848// NUL-terminated string.
849template <typename T>
850void UniversalPrint(const T& value, ::std::ostream* os) {
851 // A workarond for the bug in VC++ 7.1 that prevents us from instantiating
852 // UniversalPrinter with T directly.
853 typedef T T1;
854 UniversalPrinter<T1>::Print(value, os);
855}
856
857typedef ::std::vector< ::std::string> Strings;
858
859 // Tersely prints the first N fields of a tuple to a string vector,
860 // one element for each field.
861template <typename Tuple>
862void TersePrintPrefixToStrings(const Tuple&, std::integral_constant<size_t, 0>,
863 Strings*) {}
864template <typename Tuple, size_t I>
865void TersePrintPrefixToStrings(const Tuple& t,
866 std::integral_constant<size_t, I>,
867 Strings* strings) {
868 TersePrintPrefixToStrings(t, std::integral_constant<size_t, I - 1>(),
869 strings);
870 ::std::stringstream ss;
871 UniversalTersePrint(std::get<I - 1>(t), &ss);
872 strings->push_back(ss.str());
873}
874
875// Prints the fields of a tuple tersely to a string vector, one
876// element for each field. See the comment before
877// UniversalTersePrint() for how we define "tersely".
878template <typename Tuple>
879Strings UniversalTersePrintTupleFieldsToStrings(const Tuple& value) {
880 Strings result;
881 TersePrintPrefixToStrings(
882 value, std::integral_constant<size_t, std::tuple_size<Tuple>::value>(),
883 &result);
884 return result;
885}
886
887} // namespace internal
888
889template <typename T>
890::std::string PrintToString(const T& value) {
891 ::std::stringstream ss;
892 internal::UniversalTersePrinter<T>::Print(value, &ss);
893 return ss.str();
894}
895
896} // namespace testing
897
898// Include any custom printer added by the local installation.
899// We must include this header at the end to make sure it can use the
900// declarations from this file.
901#include "gtest/internal/custom/gtest-printers.h"
902
903#endif // GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
904