1 // Copyright 2007, Google Inc. 2 // All rights reserved. 3 // 4 // Redistribution and use in source and binary forms, with or without 5 // modification, are permitted provided that the following conditions are 6 // met: 7 // 8 // * Redistributions of source code must retain the above copyright 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. 14 // * Neither the name of Google Inc. nor the names of its 15 // contributors may be used to endorse or promote products derived from 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 20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 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" 115 116 namespace testing { 117 118 // Definitions in the internal* namespaces are subject to change without notice. 119 // DO NOT USE THEM IN USER CODE! 120 namespace internal { 121 122 template <typename T> 123 void 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. 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> PrintValueContainerPrinter132 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.) 164 struct FunctionPointerPrinter { 165 template <typename T, typename = typename std::enable_if< 166 std::is_function<T>::value>::type> PrintValueFunctionPointerPrinter167 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 }; 178 179 struct PointerPrinter { 180 template <typename T> PrintValuePointerPrinter181 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 }; 192 193 namespace 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. 199 struct LookupBlocker {}; 200 void operator<<(LookupBlocker, LookupBlocker); 201 202 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&>())> PrintValueStreamPrinter212 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 220 221 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; 226 227 template <typename T, 228 typename = typename std::enable_if< 229 internal::HasDebugStringAndShortDebugString<T>::value>::type> PrintValueProtobufPrinter230 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 }; 238 239 struct ConvertibleToIntegerPrinter { 240 // Since T has no << operator or PrintTo() but can be implicitly 241 // converted to BiggestInt, we print it as a BiggestInt. 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. PrintValueConvertibleToIntegerPrinter247 static void PrintValue(internal::BiggestInt value, ::std::ostream* os) { 248 *os << value; 249 } 250 }; 251 252 struct ConvertibleToStringViewPrinter { 253 #if GTEST_INTERNAL_HAS_STRING_VIEW PrintValueConvertibleToStringViewPrinter254 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. 263 GTEST_API_ void PrintBytesInObjectTo(const unsigned char* obj_bytes, 264 size_t count, 265 ::std::ostream* os); 266 struct RawBytesPrinter { 267 // SFINAE on `sizeof` to make sure we have a complete type. 268 template <typename T, size_t = sizeof(T)> PrintValueRawBytesPrinter269 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 }; 277 278 struct FallbackPrinter { 279 template <typename T> PrintValueFallbackPrinter280 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. 286 template <typename T, typename E, typename Printer, typename... Printers> 287 struct FindFirstPrinter : FindFirstPrinter<T, E, Printers...> {}; 288 289 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; 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. 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); 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. 330 template <typename ToPrint, typename OtherOperand> 331 class FormatForComparison { 332 public: 333 static ::std::string Format(const ToPrint& value) { 334 return ::testing::PrintToString(value); 335 } 336 }; 337 338 // Array. 339 template <typename ToPrint, size_t N, typename OtherOperand> 340 class 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 } 358 359 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); 363 #ifdef __cpp_char8_t 364 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char8_t); 365 GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char8_t); 366 #endif 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); 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 } 385 386 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::std::string); 387 GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::std::string); 388 #ifdef __cpp_char8_t 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); 391 #endif 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); 396 397 #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); 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. 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); 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. 425 template <typename T> 426 class 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). 439 template <typename T> 440 void 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. 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); 456 } 457 458 // Overloads for other simple built-in types. 459 inline 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. 470 GTEST_API_ void PrintTo(wchar_t wc, ::std::ostream* os); 471 472 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); 475 } 476 #ifdef __cpp_char8_t 477 inline void PrintTo(char8_t c, ::std::ostream* os) { 478 PrintTo(ImplicitCast_<char32_t>(c), os); 479 } 480 #endif 481 482 // 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); 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. 490 inline void PrintTo(const signed char* s, ::std::ostream* os) { 491 PrintTo(ImplicitCast_<const void*>(s), os); 492 } 493 inline void PrintTo(signed char* s, ::std::ostream* os) { 494 PrintTo(ImplicitCast_<const void*>(s), os); 495 } 496 inline void PrintTo(const unsigned char* s, ::std::ostream* os) { 497 PrintTo(ImplicitCast_<const void*>(s), os); 498 } 499 inline 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. 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); 507 } 508 #endif 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); 513 } 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); 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 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); 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. 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++) { 542 *os << ", "; 543 UniversalPrint(a[i], os); 544 } 545 } 546 547 // 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); 551 } 552 553 // Overloads for ::std::u8string 554 #ifdef __cpp_char8_t 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); 558 } 559 #endif 560 561 // 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); 565 } 566 567 // 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); 571 } 572 573 // 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); 578 } 579 #endif // GTEST_HAS_STD_WSTRING 580 581 #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); 585 } 586 #endif // GTEST_INTERNAL_HAS_STRING_VIEW 587 588 inline void PrintTo(std::nullptr_t, ::std::ostream* os) { *os << "(nullptr)"; } 589 590 template <typename T> 591 void PrintTo(std::reference_wrapper<T> ref, ::std::ostream* os) { 592 UniversalPrinter<T&>::Print(ref.get(), os); 593 } 594 595 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); 598 } 599 600 template <typename T, typename Ptr> 601 void 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 } 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) { 614 *os << "(nullptr)"; 615 } else { 616 *os << "(ptr = " << (VoidifyPointer)(ptr.get()) << ", value = "; 617 UniversalPrinter<T>::Print(*ptr, os); 618 *os << ")"; 619 } 620 } 621 622 template <typename T, typename D> 623 void PrintTo(const std::unique_ptr<T, D>& ptr, std::ostream* os) { 624 (PrintSmartPointer<T>)(ptr, os, 0); 625 } 626 627 template <typename T> 628 void 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. 634 template <typename T> 635 void PrintTupleTo(const T&, std::integral_constant<size_t, 0>, 636 ::std::ostream*) {} 637 638 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_() 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 } 650 651 template <typename... Types> 652 void 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. 659 template <typename T1, typename T2> 660 void 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. 672 template <typename T> 673 class 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. 698 template <typename T> 699 class UniversalPrinter<const T> : public UniversalPrinter<T> {}; 700 701 #if GTEST_INTERNAL_HAS_ANY 702 703 // Printer for std::any / absl::any 704 705 template <> 706 class 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 732 733 template <typename T> 734 class 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 752 753 template <typename... T> 754 class 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'. 783 template <typename T> 784 void 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. 805 GTEST_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. 810 GTEST_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. 815 GTEST_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. 819 GTEST_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. 823 GTEST_API_ void UniversalPrintArray( 824 const wchar_t* begin, size_t len, ::std::ostream* os); 825 826 // Implements printing an array type T[N]. 827 template <typename T, size_t N> 828 class 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&. 838 template <typename T> 839 class 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. 860 861 template <typename T> 862 class UniversalTersePrinter { 863 public: 864 static void Print(const T& value, ::std::ostream* os) { 865 UniversalPrint(value, os); 866 } 867 }; 868 template <typename T> 869 class UniversalTersePrinter<T&> { 870 public: 871 static void Print(const T& value, ::std::ostream* os) { 872 UniversalPrint(value, os); 873 } 874 }; 875 template <typename T, size_t N> 876 class 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 }; 882 template <> 883 class 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 }; 893 template <> 894 class UniversalTersePrinter<char*> : public UniversalTersePrinter<const char*> { 895 }; 896 897 #ifdef __cpp_char8_t 898 template <> 899 class 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 }; 909 template <> 910 class UniversalTersePrinter<char8_t*> 911 : public UniversalTersePrinter<const char8_t*> {}; 912 #endif 913 914 template <> 915 class 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 }; 925 template <> 926 class UniversalTersePrinter<char16_t*> 927 : public UniversalTersePrinter<const char16_t*> {}; 928 929 template <> 930 class 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 }; 940 template <> 941 class UniversalTersePrinter<char32_t*> 942 : public UniversalTersePrinter<const char32_t*> {}; 943 944 #if GTEST_HAS_STD_WSTRING 945 template <> 946 class 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 957 958 template <> 959 class 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 }; 965 966 template <typename T> 967 void 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. 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. 979 typedef T T1; 980 UniversalPrinter<T1>::Print(value, os); 981 } 982 983 typedef ::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. 987 template <typename Tuple> 988 void TersePrintPrefixToStrings(const Tuple&, std::integral_constant<size_t, 0>, 989 Strings*) {} 990 template <typename Tuple, size_t I> 991 void 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". 1004 template <typename Tuple> 1005 Strings 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 1015 template <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