1// Copyright 2007, Google Inc.
2// All rights reserved.
3//
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5// modification, are permitted provided that the following conditions are
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7//
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9// notice, this list of conditions and the following disclaimer.
10// * Redistributions in binary form must reproduce the above
11// copyright notice, this list of conditions and the following disclaimer
12// in the documentation and/or other materials provided with the
13// distribution.
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16// this software without specific prior written permission.
17//
18// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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25// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
101#define GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
102
103#include <functional>
104#include <memory>
105#include <ostream> // NOLINT
106#include <sstream>
107#include <string>
108#include <tuple>
109#include <type_traits>
110#include <utility>
111#include <vector>
112
113#include "gtest/internal/gtest-internal.h"
114#include "gtest/internal/gtest-port.h"
115
116namespace testing {
117
118// Definitions in the internal* namespaces are subject to change without notice.
119// DO NOT USE THEM IN USER CODE!
120namespace internal {
121
122template <typename T>
123void UniversalPrint(const T& value, ::std::ostream* os);
124
125// Used to print an STL-style container when the user doesn't define
126// a PrintTo() for it.
127struct 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.
134 *os << '{';
135 size_t count = 0;
136 for (auto&& elem : container) {
137 if (count > 0) {
138 *os << ',';
139 if (count == kMaxCount) { // Enough has been printed.
140 *os << " ...";
141 break;
142 }
143 }
144 *os << ' ';
145 // We cannot call PrintTo(elem, os) here as PrintTo() doesn't
146 // handle `elem` being a native array.
147 internal::UniversalPrint(elem, os);
148 ++count;
149 }
150
151 if (count > 0) {
152 *os << ' ';
153 }
154 *os << '}';
155 }
156};
157
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
163// bytes.)
164struct 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) {
168 if (p == nullptr) {
169 *os << "NULL";
170 } else {
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
173 // void*.
174 *os << reinterpret_cast<const void*>(p);
175 }
176 }
177};
178
179struct PointerPrinter {
180 template <typename T>
181 static void PrintValue(T* p, ::std::ostream* os) {
182 if (p == nullptr) {
183 *os << "NULL";
184 } else {
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
187 // types, if any.
188 *os << p;
189 }
190 }
191};
192
193namespace internal_stream_operator_without_lexical_name_lookup {
194
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
198// candidates.
199struct LookupBlocker {};
200void operator<<(LookupBlocker, LookupBlocker);
201
202struct 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
214 // of the arguments.
215 *os << value;
216 }
217};
218
219} // namespace internal_stream_operator_without_lexical_name_lookup
220
221struct 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;
226
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();
234 }
235 *os << ("<" + pretty_str + ">");
236 }
237};
238
239struct ConvertibleToIntegerPrinter {
240 // Since T has no << operator or PrintTo() but can be implicitly
241 // converted to BiggestInt, we print it as a BiggestInt.
242 //
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) {
248 *os << value;
249 }
250};
251
252struct ConvertibleToStringViewPrinter {
253#if GTEST_INTERNAL_HAS_STRING_VIEW
254 static void PrintValue(internal::StringView value, ::std::ostream* os) {
255 internal::UniversalPrint(value, os);
256 }
257#endif
258};
259
260
261// Prints the given number of bytes in the given object to the given
262// ostream.
263GTEST_API_ void PrintBytesInObjectTo(const unsigned char* obj_bytes,
264 size_t count,
265 ::std::ostream* os);
266struct 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))),
274 sizeof(value), os);
275 }
276};
277
278struct FallbackPrinter {
279 template <typename T>
280 static void PrintValue(const T&, ::std::ostream* os) {
281 *os << "(incomplete type)";
282 }
283};
284
285// Try every printer in order and return the first one that works.
286template <typename T, typename E, typename Printer, typename... Printers>
287struct FindFirstPrinter : FindFirstPrinter<T, E, Printers...> {};
288
289template <typename T, typename Printer, typename... Printers>
290struct FindFirstPrinter<
291 T, decltype(Printer::PrintValue(std::declval<const T&>(), nullptr)),
292 Printer, Printers...> {
293 using type = Printer;
294};
295
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.
305template <typename T>
306void 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);
313}
314
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.
326//
327// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
328
329// The default case.
330template <typename ToPrint, typename OtherOperand>
331class FormatForComparison {
332 public:
333 static ::std::string Format(const ToPrint& value) {
334 return ::testing::PrintToString(value);
335 }
336};
337
338// Array.
339template <typename ToPrint, size_t N, typename OtherOperand>
340class FormatForComparison<ToPrint[N], OtherOperand> {
341 public:
342 static ::std::string Format(const ToPrint* value) {
343 return FormatForComparison<const ToPrint*, OtherOperand>::Format(value);
344 }
345};
346
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.
349
350#define GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(CharType) \
351 template <typename OtherOperand> \
352 class FormatForComparison<CharType*, OtherOperand> { \
353 public: \
354 static ::std::string Format(CharType* value) { \
355 return ::testing::PrintToString(static_cast<const void*>(value)); \
356 } \
357 }
358
359GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char);
360GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char);
361GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(wchar_t);
362GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const wchar_t);
363#ifdef __cpp_char8_t
364GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char8_t);
365GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char8_t);
366#endif
367GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char16_t);
368GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char16_t);
369GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char32_t);
370GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char32_t);
371
372#undef GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_
373
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.
376
377#define GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(CharType, OtherStringType) \
378 template <> \
379 class FormatForComparison<CharType*, OtherStringType> { \
380 public: \
381 static ::std::string Format(CharType* value) { \
382 return ::testing::PrintToString(value); \
383 } \
384 }
385
386GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::std::string);
387GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::std::string);
388#ifdef __cpp_char8_t
389GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char8_t, ::std::u8string);
390GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char8_t, ::std::u8string);
391#endif
392GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char16_t, ::std::u16string);
393GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char16_t, ::std::u16string);
394GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char32_t, ::std::u32string);
395GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char32_t, ::std::u32string);
396
397#if GTEST_HAS_STD_WSTRING
398GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(wchar_t, ::std::wstring);
399GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const wchar_t, ::std::wstring);
400#endif
401
402#undef GTEST_IMPL_FORMAT_C_STRING_AS_STRING_
403
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.
410//
411// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
412template <typename T1, typename T2>
413std::string FormatForComparisonFailureMessage(
414 const T1& value, const T2& /* other_operand */) {
415 return FormatForComparison<T1, T2>::Format(value);
416}
417
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.
421//
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.
425template <typename T>
426class UniversalPrinter;
427
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.
432//
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
438// wants).
439template <typename T>
440void PrintTo(const T& value, ::std::ostream* os) {
441 internal::PrintWithFallback(value, os);
442}
443
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).
447
448// Overloads for various char types.
449GTEST_API_ void PrintTo(unsigned char c, ::std::ostream* os);
450GTEST_API_ void PrintTo(signed char c, ::std::ostream* os);
451inline 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);
456}
457
458// Overloads for other simple built-in types.
459inline void PrintTo(bool x, ::std::ostream* os) {
460 *os << (x ? "true" : "false");
461}
462
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.
470GTEST_API_ void PrintTo(wchar_t wc, ::std::ostream* os);
471
472GTEST_API_ void PrintTo(char32_t c, ::std::ostream* os);
473inline void PrintTo(char16_t c, ::std::ostream* os) {
474 PrintTo(ImplicitCast_<char32_t>(c), os);
475}
476#ifdef __cpp_char8_t
477inline void PrintTo(char8_t c, ::std::ostream* os) {
478 PrintTo(ImplicitCast_<char32_t>(c), os);
479}
480#endif
481
482// Overloads for C strings.
483GTEST_API_ void PrintTo(const char* s, ::std::ostream* os);
484inline void PrintTo(char* s, ::std::ostream* os) {
485 PrintTo(ImplicitCast_<const char*>(s), os);
486}
487
488// signed/unsigned char is often used for representing binary data, so
489// we print pointers to it as void* to be safe.
490inline void PrintTo(const signed char* s, ::std::ostream* os) {
491 PrintTo(ImplicitCast_<const void*>(s), os);
492}
493inline void PrintTo(signed char* s, ::std::ostream* os) {
494 PrintTo(ImplicitCast_<const void*>(s), os);
495}
496inline void PrintTo(const unsigned char* s, ::std::ostream* os) {
497 PrintTo(ImplicitCast_<const void*>(s), os);
498}
499inline void PrintTo(unsigned char* s, ::std::ostream* os) {
500 PrintTo(ImplicitCast_<const void*>(s), os);
501}
502#ifdef __cpp_char8_t
503// Overloads for u8 strings.
504void PrintTo(const char8_t* s, ::std::ostream* os);
505inline void PrintTo(char8_t* s, ::std::ostream* os) {
506 PrintTo(ImplicitCast_<const char8_t*>(s), os);
507}
508#endif
509// Overloads for u16 strings.
510void PrintTo(const char16_t* s, ::std::ostream* os);
511inline void PrintTo(char16_t* s, ::std::ostream* os) {
512 PrintTo(ImplicitCast_<const char16_t*>(s), os);
513}
514// Overloads for u32 strings.
515void PrintTo(const char32_t* s, ::std::ostream* os);
516inline void PrintTo(char32_t* s, ::std::ostream* os) {
517 PrintTo(ImplicitCast_<const char32_t*>(s), os);
518}
519
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
527GTEST_API_ void PrintTo(const wchar_t* s, ::std::ostream* os);
528inline void PrintTo(wchar_t* s, ::std::ostream* os) {
529 PrintTo(ImplicitCast_<const wchar_t*>(s), os);
530}
531#endif
532
533// Overload for C arrays. Multi-dimensional arrays are printed
534// properly.
535
536// Prints the given number of elements in an array, without printing
537// the curly braces.
538template <typename T>
539void PrintRawArrayTo(const T a[], size_t count, ::std::ostream* os) {
540 UniversalPrint(a[0], os);
541 for (size_t i = 1; i != count; i++) {
542 *os << ", ";
543 UniversalPrint(a[i], os);
544 }
545}
546
547// Overloads for ::std::string.
548GTEST_API_ void PrintStringTo(const ::std::string&s, ::std::ostream* os);
549inline void PrintTo(const ::std::string& s, ::std::ostream* os) {
550 PrintStringTo(s, os);
551}
552
553// Overloads for ::std::u8string
554#ifdef __cpp_char8_t
555GTEST_API_ void PrintU8StringTo(const ::std::u8string& s, ::std::ostream* os);
556inline void PrintTo(const ::std::u8string& s, ::std::ostream* os) {
557 PrintU8StringTo(s, os);
558}
559#endif
560
561// Overloads for ::std::u16string
562GTEST_API_ void PrintU16StringTo(const ::std::u16string& s, ::std::ostream* os);
563inline void PrintTo(const ::std::u16string& s, ::std::ostream* os) {
564 PrintU16StringTo(s, os);
565}
566
567// Overloads for ::std::u32string
568GTEST_API_ void PrintU32StringTo(const ::std::u32string& s, ::std::ostream* os);
569inline void PrintTo(const ::std::u32string& s, ::std::ostream* os) {
570 PrintU32StringTo(s, os);
571}
572
573// Overloads for ::std::wstring.
574#if GTEST_HAS_STD_WSTRING
575GTEST_API_ void PrintWideStringTo(const ::std::wstring&s, ::std::ostream* os);
576inline void PrintTo(const ::std::wstring& s, ::std::ostream* os) {
577 PrintWideStringTo(s, os);
578}
579#endif // GTEST_HAS_STD_WSTRING
580
581#if GTEST_INTERNAL_HAS_STRING_VIEW
582// Overload for internal::StringView.
583inline void PrintTo(internal::StringView sp, ::std::ostream* os) {
584 PrintTo(::std::string(sp), os);
585}
586#endif // GTEST_INTERNAL_HAS_STRING_VIEW
587
588inline void PrintTo(std::nullptr_t, ::std::ostream* os) { *os << "(nullptr)"; }
589
590template <typename T>
591void PrintTo(std::reference_wrapper<T> ref, ::std::ostream* os) {
592 UniversalPrinter<T&>::Print(ref.get(), os);
593}
594
595inline const void* VoidifyPointer(const void* p) { return p; }
596inline const void* VoidifyPointer(volatile const void* p) {
597 return const_cast<const void*>(p);
598}
599
600template <typename T, typename Ptr>
601void PrintSmartPointer(const Ptr& ptr, std::ostream* os, char) {
602 if (ptr == nullptr) {
603 *os << "(nullptr)";
604 } else {
605 // We can't print the value. Just print the pointer..
606 *os << "(" << (VoidifyPointer)(ptr.get()) << ")";
607 }
608}
609template <typename T, typename Ptr,
610 typename = typename std::enable_if<!std::is_void<T>::value &&
611 !std::is_array<T>::value>::type>
612void PrintSmartPointer(const Ptr& ptr, std::ostream* os, int) {
613 if (ptr == nullptr) {
614 *os << "(nullptr)";
615 } else {
616 *os << "(ptr = " << (VoidifyPointer)(ptr.get()) << ", value = ";
617 UniversalPrinter<T>::Print(*ptr, os);
618 *os << ")";
619 }
620}
621
622template <typename T, typename D>
623void PrintTo(const std::unique_ptr<T, D>& ptr, std::ostream* os) {
624 (PrintSmartPointer<T>)(ptr, os, 0);
625}
626
627template <typename T>
628void PrintTo(const std::shared_ptr<T>& ptr, std::ostream* os) {
629 (PrintSmartPointer<T>)(ptr, os, 0);
630}
631
632// Helper function for printing a tuple. T must be instantiated with
633// a tuple type.
634template <typename T>
635void PrintTupleTo(const T&, std::integral_constant<size_t, 0>,
636 ::std::ostream*) {}
637
638template <typename T, size_t I>
639void 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_()
643 if (I > 1) {
644 GTEST_INTENTIONAL_CONST_COND_POP_()
645 *os << ", ";
646 }
647 UniversalPrinter<typename std::tuple_element<I - 1, T>::type>::Print(
648 std::get<I - 1>(t), os);
649}
650
651template <typename... Types>
652void PrintTo(const ::std::tuple<Types...>& t, ::std::ostream* os) {
653 *os << "(";
654 PrintTupleTo(t, std::integral_constant<size_t, sizeof...(Types)>(), os);
655 *os << ")";
656}
657
658// Overload for std::pair.
659template <typename T1, typename T2>
660void PrintTo(const ::std::pair<T1, T2>& value, ::std::ostream* os) {
661 *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);
665 *os << ", ";
666 UniversalPrinter<T2>::Print(value.second, os);
667 *os << ')';
668}
669
670// Implements printing a non-reference type T by letting the compiler
671// pick the right overload of PrintTo() for T.
672template <typename T>
673class UniversalPrinter {
674 public:
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)
678
679 // Note: we deliberately don't call this PrintTo(), as that name
680 // conflicts with ::testing::internal::PrintTo in the body of the
681 // function.
682 static void Print(const T& value, ::std::ostream* os) {
683 // By default, ::testing::internal::PrintTo() is used for printing
684 // the value.
685 //
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.
691 PrintTo(value, os);
692 }
693
694 GTEST_DISABLE_MSC_WARNINGS_POP_()
695};
696
697// Remove any const-qualifiers before passing a type to UniversalPrinter.
698template <typename T>
699class UniversalPrinter<const T> : public UniversalPrinter<T> {};
700
701#if GTEST_INTERNAL_HAS_ANY
702
703// Printer for std::any / absl::any
704
705template <>
706class UniversalPrinter<Any> {
707 public:
708 static void Print(const Any& value, ::std::ostream* os) {
709 if (value.has_value()) {
710 *os << "value of type " << GetTypeName(value);
711 } else {
712 *os << "no value";
713 }
714 }
715
716 private:
717 static std::string GetTypeName(const Any& value) {
718#if GTEST_HAS_RTTI
719 return internal::GetTypeName(value.type());
720#else
721 static_cast<void>(value); // possibly unused
722 return "<unknown_type>";
723#endif // GTEST_HAS_RTTI
724 }
725};
726
727#endif // GTEST_INTERNAL_HAS_ANY
728
729#if GTEST_INTERNAL_HAS_OPTIONAL
730
731// Printer for std::optional / absl::optional
732
733template <typename T>
734class UniversalPrinter<Optional<T>> {
735 public:
736 static void Print(const Optional<T>& value, ::std::ostream* os) {
737 *os << '(';
738 if (!value) {
739 *os << "nullopt";
740 } else {
741 UniversalPrint(*value, os);
742 }
743 *os << ')';
744 }
745};
746
747#endif // GTEST_INTERNAL_HAS_OPTIONAL
748
749#if GTEST_INTERNAL_HAS_VARIANT
750
751// Printer for std::variant / absl::variant
752
753template <typename... T>
754class UniversalPrinter<Variant<T...>> {
755 public:
756 static void Print(const Variant<T...>& value, ::std::ostream* os) {
757 *os << '(';
758#if GTEST_HAS_ABSL
759 absl::visit(Visitor{os, value.index()}, value);
760#else
761 std::visit(Visitor{os, value.index()}, value);
762#endif // GTEST_HAS_ABSL
763 *os << ')';
764 }
765
766 private:
767 struct Visitor {
768 template <typename U>
769 void operator()(const U& u) const {
770 *os << "'" << GetTypeName<U>() << "(index = " << index
771 << ")' with value ";
772 UniversalPrint(u, os);
773 }
774 ::std::ostream* os;
775 std::size_t index;
776 };
777};
778
779#endif // GTEST_INTERNAL_HAS_VARIANT
780
781// UniversalPrintArray(begin, len, os) prints an array of 'len'
782// elements, starting at address 'begin'.
783template <typename T>
784void UniversalPrintArray(const T* begin, size_t len, ::std::ostream* os) {
785 if (len == 0) {
786 *os << "{}";
787 } else {
788 *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);
796 } else {
797 PrintRawArrayTo(begin, kChunkSize, os);
798 *os << ", ..., ";
799 PrintRawArrayTo(begin + len - kChunkSize, kChunkSize, os);
800 }
801 *os << " }";
802 }
803}
804// This overload prints a (const) char array compactly.
805GTEST_API_ void UniversalPrintArray(
806 const char* begin, size_t len, ::std::ostream* os);
807
808#ifdef __cpp_char8_t
809// This overload prints a (const) char8_t array compactly.
810GTEST_API_ void UniversalPrintArray(const char8_t* begin, size_t len,
811 ::std::ostream* os);
812#endif
813
814// This overload prints a (const) char16_t array compactly.
815GTEST_API_ void UniversalPrintArray(const char16_t* begin, size_t len,
816 ::std::ostream* os);
817
818// This overload prints a (const) char32_t array compactly.
819GTEST_API_ void UniversalPrintArray(const char32_t* begin, size_t len,
820 ::std::ostream* os);
821
822// This overload prints a (const) wchar_t array compactly.
823GTEST_API_ void UniversalPrintArray(
824 const wchar_t* begin, size_t len, ::std::ostream* os);
825
826// Implements printing an array type T[N].
827template <typename T, size_t N>
828class UniversalPrinter<T[N]> {
829 public:
830 // Prints the given array, omitting some elements when there are too
831 // many.
832 static void Print(const T (&a)[N], ::std::ostream* os) {
833 UniversalPrintArray(a, N, os);
834 }
835};
836
837// Implements printing a reference type T&.
838template <typename T>
839class UniversalPrinter<T&> {
840 public:
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)
844
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) << " ";
849
850 // Then prints the value itself.
851 UniversalPrint(value, os);
852 }
853
854 GTEST_DISABLE_MSC_WARNINGS_POP_()
855};
856
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.
860
861template <typename T>
862class UniversalTersePrinter {
863 public:
864 static void Print(const T& value, ::std::ostream* os) {
865 UniversalPrint(value, os);
866 }
867};
868template <typename T>
869class UniversalTersePrinter<T&> {
870 public:
871 static void Print(const T& value, ::std::ostream* os) {
872 UniversalPrint(value, os);
873 }
874};
875template <typename T, size_t N>
876class UniversalTersePrinter<T[N]> {
877 public:
878 static void Print(const T (&value)[N], ::std::ostream* os) {
879 UniversalPrinter<T[N]>::Print(value, os);
880 }
881};
882template <>
883class UniversalTersePrinter<const char*> {
884 public:
885 static void Print(const char* str, ::std::ostream* os) {
886 if (str == nullptr) {
887 *os << "NULL";
888 } else {
889 UniversalPrint(std::string(str), os);
890 }
891 }
892};
893template <>
894class UniversalTersePrinter<char*> : public UniversalTersePrinter<const char*> {
895};
896
897#ifdef __cpp_char8_t
898template <>
899class UniversalTersePrinter<const char8_t*> {
900 public:
901 static void Print(const char8_t* str, ::std::ostream* os) {
902 if (str == nullptr) {
903 *os << "NULL";
904 } else {
905 UniversalPrint(::std::u8string(str), os);
906 }
907 }
908};
909template <>
910class UniversalTersePrinter<char8_t*>
911 : public UniversalTersePrinter<const char8_t*> {};
912#endif
913
914template <>
915class UniversalTersePrinter<const char16_t*> {
916 public:
917 static void Print(const char16_t* str, ::std::ostream* os) {
918 if (str == nullptr) {
919 *os << "NULL";
920 } else {
921 UniversalPrint(::std::u16string(str), os);
922 }
923 }
924};
925template <>
926class UniversalTersePrinter<char16_t*>
927 : public UniversalTersePrinter<const char16_t*> {};
928
929template <>
930class UniversalTersePrinter<const char32_t*> {
931 public:
932 static void Print(const char32_t* str, ::std::ostream* os) {
933 if (str == nullptr) {
934 *os << "NULL";
935 } else {
936 UniversalPrint(::std::u32string(str), os);
937 }
938 }
939};
940template <>
941class UniversalTersePrinter<char32_t*>
942 : public UniversalTersePrinter<const char32_t*> {};
943
944#if GTEST_HAS_STD_WSTRING
945template <>
946class UniversalTersePrinter<const wchar_t*> {
947 public:
948 static void Print(const wchar_t* str, ::std::ostream* os) {
949 if (str == nullptr) {
950 *os << "NULL";
951 } else {
952 UniversalPrint(::std::wstring(str), os);
953 }
954 }
955};
956#endif
957
958template <>
959class UniversalTersePrinter<wchar_t*> {
960 public:
961 static void Print(wchar_t* str, ::std::ostream* os) {
962 UniversalTersePrinter<const wchar_t*>::Print(str, os);
963 }
964};
965
966template <typename T>
967void UniversalTersePrint(const T& value, ::std::ostream* os) {
968 UniversalTersePrinter<T>::Print(value, os);
969}
970
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.
975template <typename T>
976void 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.
979 typedef T T1;
980 UniversalPrinter<T1>::Print(value, os);
981}
982
983typedef ::std::vector< ::std::string> Strings;
984
985 // Tersely prints the first N fields of a tuple to a string vector,
986 // one element for each field.
987template <typename Tuple>
988void TersePrintPrefixToStrings(const Tuple&, std::integral_constant<size_t, 0>,
989 Strings*) {}
990template <typename Tuple, size_t I>
991void TersePrintPrefixToStrings(const Tuple& t,
992 std::integral_constant<size_t, I>,
993 Strings* strings) {
994 TersePrintPrefixToStrings(t, std::integral_constant<size_t, I - 1>(),
995 strings);
996 ::std::stringstream ss;
997 UniversalTersePrint(std::get<I - 1>(t), &ss);
998 strings->push_back(ss.str());
999}
1000
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".
1004template <typename Tuple>
1005Strings UniversalTersePrintTupleFieldsToStrings(const Tuple& value) {
1006 Strings result;
1007 TersePrintPrefixToStrings(
1008 value, std::integral_constant<size_t, std::tuple_size<Tuple>::value>(),
1009 &result);
1010 return result;
1011}
1012
1013} // namespace internal
1014
1015template <typename T>
1016::std::string PrintToString(const T& value) {
1017 ::std::stringstream ss;
1018 internal::UniversalTersePrinter<T>::Print(value, &ss);
1019 return ss.str();
1020}
1021
1022} // namespace testing
1023
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"
1028
1029#endif // GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
1030