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// Author: wan@google.com (Zhanyong Wan) 31 32// Google Test - The Google C++ Testing Framework 33// 34// This file implements a universal value printer that can print a 35// value of any type T: 36// 37// void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr); 38// 39// A user can teach this function how to print a class type T by 40// defining either operator<<() or PrintTo() in the namespace that 41// defines T. More specifically, the FIRST defined function in the 42// following list will be used (assuming T is defined in namespace 43// foo): 44// 45// 1. foo::PrintTo(const T&, ostream*) 46// 2. operator<<(ostream&, const T&) defined in either foo or the 47// global namespace. 48// 49// If none of the above is defined, it will print the debug string of 50// the value if it is a protocol buffer, or print the raw bytes in the 51// value otherwise. 52// 53// To aid debugging: when T is a reference type, the address of the 54// value is also printed; when T is a (const) char pointer, both the 55// pointer value and the NUL-terminated string it points to are 56// printed. 57// 58// We also provide some convenient wrappers: 59// 60// // Prints a value to a string. For a (const or not) char 61// // pointer, the NUL-terminated string (but not the pointer) is 62// // printed. 63// std::string ::testing::PrintToString(const T& value); 64// 65// // Prints a value tersely: for a reference type, the referenced 66// // value (but not the address) is printed; for a (const or not) char 67// // pointer, the NUL-terminated string (but not the pointer) is 68// // printed. 69// void ::testing::internal::UniversalTersePrint(const T& value, ostream*); 70// 71// // Prints value using the type inferred by the compiler. The difference 72// // from UniversalTersePrint() is that this function prints both the 73// // pointer and the NUL-terminated string for a (const or not) char pointer. 74// void ::testing::internal::UniversalPrint(const T& value, ostream*); 75// 76// // Prints the fields of a tuple tersely to a string vector, one 77// // element for each field. Tuple support must be enabled in 78// // gtest-port.h. 79// std::vector<string> UniversalTersePrintTupleFieldsToStrings( 80// const Tuple& value); 81// 82// Known limitation: 83// 84// The print primitives print the elements of an STL-style container 85// using the compiler-inferred type of *iter where iter is a 86// const_iterator of the container. When const_iterator is an input 87// iterator but not a forward iterator, this inferred type may not 88// match value_type, and the print output may be incorrect. In 89// practice, this is rarely a problem as for most containers 90// const_iterator is a forward iterator. We'll fix this if there's an 91// actual need for it. Note that this fix cannot rely on value_type 92// being defined as many user-defined container types don't have 93// value_type. 94 95#ifndef GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_ 96#define GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_ 97 98#include <ostream> // NOLINT 99#include <sstream> 100#include <string> 101#include <utility> 102#include <vector> 103#include "gtest/internal/gtest-port.h" 104#include "gtest/internal/gtest-internal.h" 105 106#if GTEST_HAS_STD_TUPLE_ 107# include <tuple> 108#endif 109 110namespace testing { 111 112// Definitions in the 'internal' and 'internal2' name spaces are 113// subject to change without notice. DO NOT USE THEM IN USER CODE! 114namespace internal2 { 115 116// Prints the given number of bytes in the given object to the given 117// ostream. 118GTEST_API_ void PrintBytesInObjectTo(const unsigned char* obj_bytes, 119 size_t count, 120 ::std::ostream* os); 121 122// For selecting which printer to use when a given type has neither << 123// nor PrintTo(). 124enum TypeKind { 125 kProtobuf, // a protobuf type 126 kConvertibleToInteger, // a type implicitly convertible to BiggestInt 127 // (e.g. a named or unnamed enum type) 128 kOtherType // anything else 129}; 130 131// TypeWithoutFormatter<T, kTypeKind>::PrintValue(value, os) is called 132// by the universal printer to print a value of type T when neither 133// operator<< nor PrintTo() is defined for T, where kTypeKind is the 134// "kind" of T as defined by enum TypeKind. 135template <typename T, TypeKind kTypeKind> 136class TypeWithoutFormatter { 137 public: 138 // This default version is called when kTypeKind is kOtherType. 139 static void PrintValue(const T& value, ::std::ostream* os) { 140 PrintBytesInObjectTo(reinterpret_cast<const unsigned char*>(&value), 141 sizeof(value), os); 142 } 143}; 144 145// We print a protobuf using its ShortDebugString() when the string 146// doesn't exceed this many characters; otherwise we print it using 147// DebugString() for better readability. 148const size_t kProtobufOneLinerMaxLength = 50; 149 150template <typename T> 151class TypeWithoutFormatter<T, kProtobuf> { 152 public: 153 static void PrintValue(const T& value, ::std::ostream* os) { 154 const ::testing::internal::string short_str = value.ShortDebugString(); 155 const ::testing::internal::string pretty_str = 156 short_str.length() <= kProtobufOneLinerMaxLength ? 157 short_str : ("\n" + value.DebugString()); 158 *os << ("<" + pretty_str + ">"); 159 } 160}; 161 162template <typename T> 163class TypeWithoutFormatter<T, kConvertibleToInteger> { 164 public: 165 // Since T has no << operator or PrintTo() but can be implicitly 166 // converted to BiggestInt, we print it as a BiggestInt. 167 // 168 // Most likely T is an enum type (either named or unnamed), in which 169 // case printing it as an integer is the desired behavior. In case 170 // T is not an enum, printing it as an integer is the best we can do 171 // given that it has no user-defined printer. 172 static void PrintValue(const T& value, ::std::ostream* os) { 173 const internal::BiggestInt kBigInt = value; 174 *os << kBigInt; 175 } 176}; 177 178// Prints the given value to the given ostream. If the value is a 179// protocol message, its debug string is printed; if it's an enum or 180// of a type implicitly convertible to BiggestInt, it's printed as an 181// integer; otherwise the bytes in the value are printed. This is 182// what UniversalPrinter<T>::Print() does when it knows nothing about 183// type T and T has neither << operator nor PrintTo(). 184// 185// A user can override this behavior for a class type Foo by defining 186// a << operator in the namespace where Foo is defined. 187// 188// We put this operator in namespace 'internal2' instead of 'internal' 189// to simplify the implementation, as much code in 'internal' needs to 190// use << in STL, which would conflict with our own << were it defined 191// in 'internal'. 192// 193// Note that this operator<< takes a generic std::basic_ostream<Char, 194// CharTraits> type instead of the more restricted std::ostream. If 195// we define it to take an std::ostream instead, we'll get an 196// "ambiguous overloads" compiler error when trying to print a type 197// Foo that supports streaming to std::basic_ostream<Char, 198// CharTraits>, as the compiler cannot tell whether 199// operator<<(std::ostream&, const T&) or 200// operator<<(std::basic_stream<Char, CharTraits>, const Foo&) is more 201// specific. 202template <typename Char, typename CharTraits, typename T> 203::std::basic_ostream<Char, CharTraits>& operator<<( 204 ::std::basic_ostream<Char, CharTraits>& os, const T& x) { 205 TypeWithoutFormatter<T, 206 (internal::IsAProtocolMessage<T>::value ? kProtobuf : 207 internal::ImplicitlyConvertible<const T&, internal::BiggestInt>::value ? 208 kConvertibleToInteger : kOtherType)>::PrintValue(x, &os); 209 return os; 210} 211 212} // namespace internal2 213} // namespace testing 214 215// This namespace MUST NOT BE NESTED IN ::testing, or the name look-up 216// magic needed for implementing UniversalPrinter won't work. 217namespace testing_internal { 218 219// Used to print a value that is not an STL-style container when the 220// user doesn't define PrintTo() for it. 221template <typename T> 222void DefaultPrintNonContainerTo(const T& value, ::std::ostream* os) { 223 // With the following statement, during unqualified name lookup, 224 // testing::internal2::operator<< appears as if it was declared in 225 // the nearest enclosing namespace that contains both 226 // ::testing_internal and ::testing::internal2, i.e. the global 227 // namespace. For more details, refer to the C++ Standard section 228 // 7.3.4-1 [namespace.udir]. This allows us to fall back onto 229 // testing::internal2::operator<< in case T doesn't come with a << 230 // operator. 231 // 232 // We cannot write 'using ::testing::internal2::operator<<;', which 233 // gcc 3.3 fails to compile due to a compiler bug. 234 using namespace ::testing::internal2; // NOLINT 235 236 // Assuming T is defined in namespace foo, in the next statement, 237 // the compiler will consider all of: 238 // 239 // 1. foo::operator<< (thanks to Koenig look-up), 240 // 2. ::operator<< (as the current namespace is enclosed in ::), 241 // 3. testing::internal2::operator<< (thanks to the using statement above). 242 // 243 // The operator<< whose type matches T best will be picked. 244 // 245 // We deliberately allow #2 to be a candidate, as sometimes it's 246 // impossible to define #1 (e.g. when foo is ::std, defining 247 // anything in it is undefined behavior unless you are a compiler 248 // vendor.). 249 *os << value; 250} 251 252} // namespace testing_internal 253 254namespace testing { 255namespace internal { 256 257// FormatForComparison<ToPrint, OtherOperand>::Format(value) formats a 258// value of type ToPrint that is an operand of a comparison assertion 259// (e.g. ASSERT_EQ). OtherOperand is the type of the other operand in 260// the comparison, and is used to help determine the best way to 261// format the value. In particular, when the value is a C string 262// (char pointer) and the other operand is an STL string object, we 263// want to format the C string as a string, since we know it is 264// compared by value with the string object. If the value is a char 265// pointer but the other operand is not an STL string object, we don't 266// know whether the pointer is supposed to point to a NUL-terminated 267// string, and thus want to print it as a pointer to be safe. 268// 269// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM. 270 271// The default case. 272template <typename ToPrint, typename OtherOperand> 273class FormatForComparison { 274 public: 275 static ::std::string Format(const ToPrint& value) { 276 return ::testing::PrintToString(value); 277 } 278}; 279 280// Array. 281template <typename ToPrint, size_t N, typename OtherOperand> 282class FormatForComparison<ToPrint[N], OtherOperand> { 283 public: 284 static ::std::string Format(const ToPrint* value) { 285 return FormatForComparison<const ToPrint*, OtherOperand>::Format(value); 286 } 287}; 288 289// By default, print C string as pointers to be safe, as we don't know 290// whether they actually point to a NUL-terminated string. 291 292#define GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(CharType) \ 293 template <typename OtherOperand> \ 294 class FormatForComparison<CharType*, OtherOperand> { \ 295 public: \ 296 static ::std::string Format(CharType* value) { \ 297 return ::testing::PrintToString(static_cast<const void*>(value)); \ 298 } \ 299 } 300 301GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char); 302GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char); 303GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(wchar_t); 304GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const wchar_t); 305 306#undef GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_ 307 308// If a C string is compared with an STL string object, we know it's meant 309// to point to a NUL-terminated string, and thus can print it as a string. 310 311#define GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(CharType, OtherStringType) \ 312 template <> \ 313 class FormatForComparison<CharType*, OtherStringType> { \ 314 public: \ 315 static ::std::string Format(CharType* value) { \ 316 return ::testing::PrintToString(value); \ 317 } \ 318 } 319 320GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::std::string); 321GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::std::string); 322 323#if GTEST_HAS_GLOBAL_STRING 324GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::string); 325GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::string); 326#endif 327 328#if GTEST_HAS_GLOBAL_WSTRING 329GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(wchar_t, ::wstring); 330GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const wchar_t, ::wstring); 331#endif 332 333#if GTEST_HAS_STD_WSTRING 334GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(wchar_t, ::std::wstring); 335GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const wchar_t, ::std::wstring); 336#endif 337 338#undef GTEST_IMPL_FORMAT_C_STRING_AS_STRING_ 339 340// Formats a comparison assertion (e.g. ASSERT_EQ, EXPECT_LT, and etc) 341// operand to be used in a failure message. The type (but not value) 342// of the other operand may affect the format. This allows us to 343// print a char* as a raw pointer when it is compared against another 344// char* or void*, and print it as a C string when it is compared 345// against an std::string object, for example. 346// 347// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM. 348template <typename T1, typename T2> 349std::string FormatForComparisonFailureMessage( 350 const T1& value, const T2& /* other_operand */) { 351 return FormatForComparison<T1, T2>::Format(value); 352} 353 354// UniversalPrinter<T>::Print(value, ostream_ptr) prints the given 355// value to the given ostream. The caller must ensure that 356// 'ostream_ptr' is not NULL, or the behavior is undefined. 357// 358// We define UniversalPrinter as a class template (as opposed to a 359// function template), as we need to partially specialize it for 360// reference types, which cannot be done with function templates. 361template <typename T> 362class UniversalPrinter; 363 364template <typename T> 365void UniversalPrint(const T& value, ::std::ostream* os); 366 367// Used to print an STL-style container when the user doesn't define 368// a PrintTo() for it. 369template <typename C> 370void DefaultPrintTo(IsContainer /* dummy */, 371 false_type /* is not a pointer */, 372 const C& container, ::std::ostream* os) { 373 const size_t kMaxCount = 32; // The maximum number of elements to print. 374 *os << '{'; 375 size_t count = 0; 376 for (typename C::const_iterator it = container.begin(); 377 it != container.end(); ++it, ++count) { 378 if (count > 0) { 379 *os << ','; 380 if (count == kMaxCount) { // Enough has been printed. 381 *os << " ..."; 382 break; 383 } 384 } 385 *os << ' '; 386 // We cannot call PrintTo(*it, os) here as PrintTo() doesn't 387 // handle *it being a native array. 388 internal::UniversalPrint(*it, os); 389 } 390 391 if (count > 0) { 392 *os << ' '; 393 } 394 *os << '}'; 395} 396 397// Used to print a pointer that is neither a char pointer nor a member 398// pointer, when the user doesn't define PrintTo() for it. (A member 399// variable pointer or member function pointer doesn't really point to 400// a location in the address space. Their representation is 401// implementation-defined. Therefore they will be printed as raw 402// bytes.) 403template <typename T> 404void DefaultPrintTo(IsNotContainer /* dummy */, 405 true_type /* is a pointer */, 406 T* p, ::std::ostream* os) { 407 if (p == NULL) { 408 *os << "NULL"; 409 } else { 410 // C++ doesn't allow casting from a function pointer to any object 411 // pointer. 412 // 413 // IsTrue() silences warnings: "Condition is always true", 414 // "unreachable code". 415 if (IsTrue(ImplicitlyConvertible<T*, const void*>::value)) { 416 // T is not a function type. We just call << to print p, 417 // relying on ADL to pick up user-defined << for their pointer 418 // types, if any. 419 *os << p; 420 } else { 421 // T is a function type, so '*os << p' doesn't do what we want 422 // (it just prints p as bool). We want to print p as a const 423 // void*. However, we cannot cast it to const void* directly, 424 // even using reinterpret_cast, as earlier versions of gcc 425 // (e.g. 3.4.5) cannot compile the cast when p is a function 426 // pointer. Casting to UInt64 first solves the problem. 427 *os << reinterpret_cast<const void*>( 428 reinterpret_cast<internal::UInt64>(p)); 429 } 430 } 431} 432 433// Used to print a non-container, non-pointer value when the user 434// doesn't define PrintTo() for it. 435template <typename T> 436void DefaultPrintTo(IsNotContainer /* dummy */, 437 false_type /* is not a pointer */, 438 const T& value, ::std::ostream* os) { 439 ::testing_internal::DefaultPrintNonContainerTo(value, os); 440} 441 442// Prints the given value using the << operator if it has one; 443// otherwise prints the bytes in it. This is what 444// UniversalPrinter<T>::Print() does when PrintTo() is not specialized 445// or overloaded for type T. 446// 447// A user can override this behavior for a class type Foo by defining 448// an overload of PrintTo() in the namespace where Foo is defined. We 449// give the user this option as sometimes defining a << operator for 450// Foo is not desirable (e.g. the coding style may prevent doing it, 451// or there is already a << operator but it doesn't do what the user 452// wants). 453template <typename T> 454void PrintTo(const T& value, ::std::ostream* os) { 455 // DefaultPrintTo() is overloaded. The type of its first two 456 // arguments determine which version will be picked. If T is an 457 // STL-style container, the version for container will be called; if 458 // T is a pointer, the pointer version will be called; otherwise the 459 // generic version will be called. 460 // 461 // Note that we check for container types here, prior to we check 462 // for protocol message types in our operator<<. The rationale is: 463 // 464 // For protocol messages, we want to give people a chance to 465 // override Google Mock's format by defining a PrintTo() or 466 // operator<<. For STL containers, other formats can be 467 // incompatible with Google Mock's format for the container 468 // elements; therefore we check for container types here to ensure 469 // that our format is used. 470 // 471 // The second argument of DefaultPrintTo() is needed to bypass a bug 472 // in Symbian's C++ compiler that prevents it from picking the right 473 // overload between: 474 // 475 // PrintTo(const T& x, ...); 476 // PrintTo(T* x, ...); 477 DefaultPrintTo(IsContainerTest<T>(0), is_pointer<T>(), value, os); 478} 479 480// The following list of PrintTo() overloads tells 481// UniversalPrinter<T>::Print() how to print standard types (built-in 482// types, strings, plain arrays, and pointers). 483 484// Overloads for various char types. 485GTEST_API_ void PrintTo(unsigned char c, ::std::ostream* os); 486GTEST_API_ void PrintTo(signed char c, ::std::ostream* os); 487inline void PrintTo(char c, ::std::ostream* os) { 488 // When printing a plain char, we always treat it as unsigned. This 489 // way, the output won't be affected by whether the compiler thinks 490 // char is signed or not. 491 PrintTo(static_cast<unsigned char>(c), os); 492} 493 494// Overloads for other simple built-in types. 495inline void PrintTo(bool x, ::std::ostream* os) { 496 *os << (x ? "true" : "false"); 497} 498 499// Overload for wchar_t type. 500// Prints a wchar_t as a symbol if it is printable or as its internal 501// code otherwise and also as its decimal code (except for L'\0'). 502// The L'\0' char is printed as "L'\\0'". The decimal code is printed 503// as signed integer when wchar_t is implemented by the compiler 504// as a signed type and is printed as an unsigned integer when wchar_t 505// is implemented as an unsigned type. 506GTEST_API_ void PrintTo(wchar_t wc, ::std::ostream* os); 507 508// Overloads for C strings. 509GTEST_API_ void PrintTo(const char* s, ::std::ostream* os); 510inline void PrintTo(char* s, ::std::ostream* os) { 511 PrintTo(ImplicitCast_<const char*>(s), os); 512} 513 514// signed/unsigned char is often used for representing binary data, so 515// we print pointers to it as void* to be safe. 516inline void PrintTo(const signed char* s, ::std::ostream* os) { 517 PrintTo(ImplicitCast_<const void*>(s), os); 518} 519inline void PrintTo(signed char* s, ::std::ostream* os) { 520 PrintTo(ImplicitCast_<const void*>(s), os); 521} 522inline void PrintTo(const unsigned char* s, ::std::ostream* os) { 523 PrintTo(ImplicitCast_<const void*>(s), os); 524} 525inline void PrintTo(unsigned char* s, ::std::ostream* os) { 526 PrintTo(ImplicitCast_<const void*>(s), os); 527} 528 529// MSVC can be configured to define wchar_t as a typedef of unsigned 530// short. It defines _NATIVE_WCHAR_T_DEFINED when wchar_t is a native 531// type. When wchar_t is a typedef, defining an overload for const 532// wchar_t* would cause unsigned short* be printed as a wide string, 533// possibly causing invalid memory accesses. 534#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED) 535// Overloads for wide C strings 536GTEST_API_ void PrintTo(const wchar_t* s, ::std::ostream* os); 537inline void PrintTo(wchar_t* s, ::std::ostream* os) { 538 PrintTo(ImplicitCast_<const wchar_t*>(s), os); 539} 540#endif 541 542// Overload for C arrays. Multi-dimensional arrays are printed 543// properly. 544 545// Prints the given number of elements in an array, without printing 546// the curly braces. 547template <typename T> 548void PrintRawArrayTo(const T a[], size_t count, ::std::ostream* os) { 549 UniversalPrint(a[0], os); 550 for (size_t i = 1; i != count; i++) { 551 *os << ", "; 552 UniversalPrint(a[i], os); 553 } 554} 555 556// Overloads for ::string and ::std::string. 557#if GTEST_HAS_GLOBAL_STRING 558GTEST_API_ void PrintStringTo(const ::string&s, ::std::ostream* os); 559inline void PrintTo(const ::string& s, ::std::ostream* os) { 560 PrintStringTo(s, os); 561} 562#endif // GTEST_HAS_GLOBAL_STRING 563 564GTEST_API_ void PrintStringTo(const ::std::string&s, ::std::ostream* os); 565inline void PrintTo(const ::std::string& s, ::std::ostream* os) { 566 PrintStringTo(s, os); 567} 568 569// Overloads for ::wstring and ::std::wstring. 570#if GTEST_HAS_GLOBAL_WSTRING 571GTEST_API_ void PrintWideStringTo(const ::wstring&s, ::std::ostream* os); 572inline void PrintTo(const ::wstring& s, ::std::ostream* os) { 573 PrintWideStringTo(s, os); 574} 575#endif // GTEST_HAS_GLOBAL_WSTRING 576 577#if GTEST_HAS_STD_WSTRING 578GTEST_API_ void PrintWideStringTo(const ::std::wstring&s, ::std::ostream* os); 579inline void PrintTo(const ::std::wstring& s, ::std::ostream* os) { 580 PrintWideStringTo(s, os); 581} 582#endif // GTEST_HAS_STD_WSTRING 583 584#if GTEST_HAS_TR1_TUPLE || GTEST_HAS_STD_TUPLE_ 585// Helper function for printing a tuple. T must be instantiated with 586// a tuple type. 587template <typename T> 588void PrintTupleTo(const T& t, ::std::ostream* os); 589#endif // GTEST_HAS_TR1_TUPLE || GTEST_HAS_STD_TUPLE_ 590 591#if GTEST_HAS_TR1_TUPLE 592// Overload for ::std::tr1::tuple. Needed for printing function arguments, 593// which are packed as tuples. 594 595// Overloaded PrintTo() for tuples of various arities. We support 596// tuples of up-to 10 fields. The following implementation works 597// regardless of whether tr1::tuple is implemented using the 598// non-standard variadic template feature or not. 599 600inline void PrintTo(const ::std::tr1::tuple<>& t, ::std::ostream* os) { 601 PrintTupleTo(t, os); 602} 603 604template <typename T1> 605void PrintTo(const ::std::tr1::tuple<T1>& t, ::std::ostream* os) { 606 PrintTupleTo(t, os); 607} 608 609template <typename T1, typename T2> 610void PrintTo(const ::std::tr1::tuple<T1, T2>& t, ::std::ostream* os) { 611 PrintTupleTo(t, os); 612} 613 614template <typename T1, typename T2, typename T3> 615void PrintTo(const ::std::tr1::tuple<T1, T2, T3>& t, ::std::ostream* os) { 616 PrintTupleTo(t, os); 617} 618 619template <typename T1, typename T2, typename T3, typename T4> 620void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4>& t, ::std::ostream* os) { 621 PrintTupleTo(t, os); 622} 623 624template <typename T1, typename T2, typename T3, typename T4, typename T5> 625void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5>& t, 626 ::std::ostream* os) { 627 PrintTupleTo(t, os); 628} 629 630template <typename T1, typename T2, typename T3, typename T4, typename T5, 631 typename T6> 632void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6>& t, 633 ::std::ostream* os) { 634 PrintTupleTo(t, os); 635} 636 637template <typename T1, typename T2, typename T3, typename T4, typename T5, 638 typename T6, typename T7> 639void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6, T7>& t, 640 ::std::ostream* os) { 641 PrintTupleTo(t, os); 642} 643 644template <typename T1, typename T2, typename T3, typename T4, typename T5, 645 typename T6, typename T7, typename T8> 646void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6, T7, T8>& t, 647 ::std::ostream* os) { 648 PrintTupleTo(t, os); 649} 650 651template <typename T1, typename T2, typename T3, typename T4, typename T5, 652 typename T6, typename T7, typename T8, typename T9> 653void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9>& t, 654 ::std::ostream* os) { 655 PrintTupleTo(t, os); 656} 657 658template <typename T1, typename T2, typename T3, typename T4, typename T5, 659 typename T6, typename T7, typename T8, typename T9, typename T10> 660void PrintTo( 661 const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>& t, 662 ::std::ostream* os) { 663 PrintTupleTo(t, os); 664} 665#endif // GTEST_HAS_TR1_TUPLE 666 667#if GTEST_HAS_STD_TUPLE_ 668template <typename... Types> 669void PrintTo(const ::std::tuple<Types...>& t, ::std::ostream* os) { 670 PrintTupleTo(t, os); 671} 672#endif // GTEST_HAS_STD_TUPLE_ 673 674// Overload for std::pair. 675template <typename T1, typename T2> 676void PrintTo(const ::std::pair<T1, T2>& value, ::std::ostream* os) { 677 *os << '('; 678 // We cannot use UniversalPrint(value.first, os) here, as T1 may be 679 // a reference type. The same for printing value.second. 680 UniversalPrinter<T1>::Print(value.first, os); 681 *os << ", "; 682 UniversalPrinter<T2>::Print(value.second, os); 683 *os << ')'; 684} 685 686// Implements printing a non-reference type T by letting the compiler 687// pick the right overload of PrintTo() for T. 688template <typename T> 689class UniversalPrinter { 690 public: 691 // MSVC warns about adding const to a function type, so we want to 692 // disable the warning. 693 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180) 694 695 // Note: we deliberately don't call this PrintTo(), as that name 696 // conflicts with ::testing::internal::PrintTo in the body of the 697 // function. 698 static void Print(const T& value, ::std::ostream* os) { 699 // By default, ::testing::internal::PrintTo() is used for printing 700 // the value. 701 // 702 // Thanks to Koenig look-up, if T is a class and has its own 703 // PrintTo() function defined in its namespace, that function will 704 // be visible here. Since it is more specific than the generic ones 705 // in ::testing::internal, it will be picked by the compiler in the 706 // following statement - exactly what we want. 707 PrintTo(value, os); 708 } 709 710 GTEST_DISABLE_MSC_WARNINGS_POP_() 711}; 712 713// UniversalPrintArray(begin, len, os) prints an array of 'len' 714// elements, starting at address 'begin'. 715template <typename T> 716void UniversalPrintArray(const T* begin, size_t len, ::std::ostream* os) { 717 if (len == 0) { 718 *os << "{}"; 719 } else { 720 *os << "{ "; 721 const size_t kThreshold = 18; 722 const size_t kChunkSize = 8; 723 // If the array has more than kThreshold elements, we'll have to 724 // omit some details by printing only the first and the last 725 // kChunkSize elements. 726 // TODO(wan@google.com): let the user control the threshold using a flag. 727 if (len <= kThreshold) { 728 PrintRawArrayTo(begin, len, os); 729 } else { 730 PrintRawArrayTo(begin, kChunkSize, os); 731 *os << ", ..., "; 732 PrintRawArrayTo(begin + len - kChunkSize, kChunkSize, os); 733 } 734 *os << " }"; 735 } 736} 737// This overload prints a (const) char array compactly. 738GTEST_API_ void UniversalPrintArray( 739 const char* begin, size_t len, ::std::ostream* os); 740 741// This overload prints a (const) wchar_t array compactly. 742GTEST_API_ void UniversalPrintArray( 743 const wchar_t* begin, size_t len, ::std::ostream* os); 744 745// Implements printing an array type T[N]. 746template <typename T, size_t N> 747class UniversalPrinter<T[N]> { 748 public: 749 // Prints the given array, omitting some elements when there are too 750 // many. 751 static void Print(const T (&a)[N], ::std::ostream* os) { 752 UniversalPrintArray(a, N, os); 753 } 754}; 755 756// Implements printing a reference type T&. 757template <typename T> 758class UniversalPrinter<T&> { 759 public: 760 // MSVC warns about adding const to a function type, so we want to 761 // disable the warning. 762 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180) 763 764 static void Print(const T& value, ::std::ostream* os) { 765 // Prints the address of the value. We use reinterpret_cast here 766 // as static_cast doesn't compile when T is a function type. 767 *os << "@" << reinterpret_cast<const void*>(&value) << " "; 768 769 // Then prints the value itself. 770 UniversalPrint(value, os); 771 } 772 773 GTEST_DISABLE_MSC_WARNINGS_POP_() 774}; 775 776// Prints a value tersely: for a reference type, the referenced value 777// (but not the address) is printed; for a (const) char pointer, the 778// NUL-terminated string (but not the pointer) is printed. 779 780template <typename T> 781class UniversalTersePrinter { 782 public: 783 static void Print(const T& value, ::std::ostream* os) { 784 UniversalPrint(value, os); 785 } 786}; 787template <typename T> 788class UniversalTersePrinter<T&> { 789 public: 790 static void Print(const T& value, ::std::ostream* os) { 791 UniversalPrint(value, os); 792 } 793}; 794template <typename T, size_t N> 795class UniversalTersePrinter<T[N]> { 796 public: 797 static void Print(const T (&value)[N], ::std::ostream* os) { 798 UniversalPrinter<T[N]>::Print(value, os); 799 } 800}; 801template <> 802class UniversalTersePrinter<const char*> { 803 public: 804 static void Print(const char* str, ::std::ostream* os) { 805 if (str == NULL) { 806 *os << "NULL"; 807 } else { 808 UniversalPrint(string(str), os); 809 } 810 } 811}; 812template <> 813class UniversalTersePrinter<char*> { 814 public: 815 static void Print(char* str, ::std::ostream* os) { 816 UniversalTersePrinter<const char*>::Print(str, os); 817 } 818}; 819 820#if GTEST_HAS_STD_WSTRING 821template <> 822class UniversalTersePrinter<const wchar_t*> { 823 public: 824 static void Print(const wchar_t* str, ::std::ostream* os) { 825 if (str == NULL) { 826 *os << "NULL"; 827 } else { 828 UniversalPrint(::std::wstring(str), os); 829 } 830 } 831}; 832#endif 833 834template <> 835class UniversalTersePrinter<wchar_t*> { 836 public: 837 static void Print(wchar_t* str, ::std::ostream* os) { 838 UniversalTersePrinter<const wchar_t*>::Print(str, os); 839 } 840}; 841 842template <typename T> 843void UniversalTersePrint(const T& value, ::std::ostream* os) { 844 UniversalTersePrinter<T>::Print(value, os); 845} 846 847// Prints a value using the type inferred by the compiler. The 848// difference between this and UniversalTersePrint() is that for a 849// (const) char pointer, this prints both the pointer and the 850// NUL-terminated string. 851template <typename T> 852void UniversalPrint(const T& value, ::std::ostream* os) { 853 // A workarond for the bug in VC++ 7.1 that prevents us from instantiating 854 // UniversalPrinter with T directly. 855 typedef T T1; 856 UniversalPrinter<T1>::Print(value, os); 857} 858 859typedef ::std::vector<string> Strings; 860 861// TuplePolicy<TupleT> must provide: 862// - tuple_size 863// size of tuple TupleT. 864// - get<size_t I>(const TupleT& t) 865// static function extracting element I of tuple TupleT. 866// - tuple_element<size_t I>::type 867// type of element I of tuple TupleT. 868template <typename TupleT> 869struct TuplePolicy; 870 871#if GTEST_HAS_TR1_TUPLE 872template <typename TupleT> 873struct TuplePolicy { 874 typedef TupleT Tuple; 875 static const size_t tuple_size = ::std::tr1::tuple_size<Tuple>::value; 876 877 template <size_t I> 878 struct tuple_element : ::std::tr1::tuple_element<I, Tuple> {}; 879 880 template <size_t I> 881 static typename AddReference< 882 const typename ::std::tr1::tuple_element<I, Tuple>::type>::type get( 883 const Tuple& tuple) { 884 return ::std::tr1::get<I>(tuple); 885 } 886}; 887template <typename TupleT> 888const size_t TuplePolicy<TupleT>::tuple_size; 889#endif // GTEST_HAS_TR1_TUPLE 890 891#if GTEST_HAS_STD_TUPLE_ 892template <typename... Types> 893struct TuplePolicy< ::std::tuple<Types...> > { 894 typedef ::std::tuple<Types...> Tuple; 895 static const size_t tuple_size = ::std::tuple_size<Tuple>::value; 896 897 template <size_t I> 898 struct tuple_element : ::std::tuple_element<I, Tuple> {}; 899 900 template <size_t I> 901 static const typename ::std::tuple_element<I, Tuple>::type& get( 902 const Tuple& tuple) { 903 return ::std::get<I>(tuple); 904 } 905}; 906template <typename... Types> 907const size_t TuplePolicy< ::std::tuple<Types...> >::tuple_size; 908#endif // GTEST_HAS_STD_TUPLE_ 909 910#if GTEST_HAS_TR1_TUPLE || GTEST_HAS_STD_TUPLE_ 911// This helper template allows PrintTo() for tuples and 912// UniversalTersePrintTupleFieldsToStrings() to be defined by 913// induction on the number of tuple fields. The idea is that 914// TuplePrefixPrinter<N>::PrintPrefixTo(t, os) prints the first N 915// fields in tuple t, and can be defined in terms of 916// TuplePrefixPrinter<N - 1>. 917// 918// The inductive case. 919template <size_t N> 920struct TuplePrefixPrinter { 921 // Prints the first N fields of a tuple. 922 template <typename Tuple> 923 static void PrintPrefixTo(const Tuple& t, ::std::ostream* os) { 924 TuplePrefixPrinter<N - 1>::PrintPrefixTo(t, os); 925 GTEST_INTENTIONAL_CONST_COND_PUSH_() 926 if (N > 1) { 927 GTEST_INTENTIONAL_CONST_COND_POP_() 928 *os << ", "; 929 } 930 UniversalPrinter< 931 typename TuplePolicy<Tuple>::template tuple_element<N - 1>::type> 932 ::Print(TuplePolicy<Tuple>::template get<N - 1>(t), os); 933 } 934 935 // Tersely prints the first N fields of a tuple to a string vector, 936 // one element for each field. 937 template <typename Tuple> 938 static void TersePrintPrefixToStrings(const Tuple& t, Strings* strings) { 939 TuplePrefixPrinter<N - 1>::TersePrintPrefixToStrings(t, strings); 940 ::std::stringstream ss; 941 UniversalTersePrint(TuplePolicy<Tuple>::template get<N - 1>(t), &ss); 942 strings->push_back(ss.str()); 943 } 944}; 945 946// Base case. 947template <> 948struct TuplePrefixPrinter<0> { 949 template <typename Tuple> 950 static void PrintPrefixTo(const Tuple&, ::std::ostream*) {} 951 952 template <typename Tuple> 953 static void TersePrintPrefixToStrings(const Tuple&, Strings*) {} 954}; 955 956// Helper function for printing a tuple. 957// Tuple must be either std::tr1::tuple or std::tuple type. 958template <typename Tuple> 959void PrintTupleTo(const Tuple& t, ::std::ostream* os) { 960 *os << "("; 961 TuplePrefixPrinter<TuplePolicy<Tuple>::tuple_size>::PrintPrefixTo(t, os); 962 *os << ")"; 963} 964 965// Prints the fields of a tuple tersely to a string vector, one 966// element for each field. See the comment before 967// UniversalTersePrint() for how we define "tersely". 968template <typename Tuple> 969Strings UniversalTersePrintTupleFieldsToStrings(const Tuple& value) { 970 Strings result; 971 TuplePrefixPrinter<TuplePolicy<Tuple>::tuple_size>:: 972 TersePrintPrefixToStrings(value, &result); 973 return result; 974} 975#endif // GTEST_HAS_TR1_TUPLE || GTEST_HAS_STD_TUPLE_ 976 977} // namespace internal 978 979template <typename T> 980::std::string PrintToString(const T& value) { 981 ::std::stringstream ss; 982 internal::UniversalTersePrinter<T>::Print(value, &ss); 983 return ss.str(); 984} 985 986} // namespace testing 987 988// Include any custom printer added by the local installation. 989// We must include this header at the end to make sure it can use the 990// declarations from this file. 991#include "gtest/internal/custom/gtest-printers.h" 992 993#endif // GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_ 994