ref: 8894c766c6d9460d12e52d350e7084b143d6109b
dir: /third_party/googletest/src/include/gtest/gtest-printers.h/
// Copyright 2007, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// Google Test - The Google C++ Testing and Mocking Framework
//
// This file implements a universal value printer that can print a
// value of any type T:
//
// void ::testing::internal::UniversalPrinter<T>::Print(value, ostream_ptr);
//
// A user can teach this function how to print a class type T by
// defining either operator<<() or PrintTo() in the namespace that
// defines T. More specifically, the FIRST defined function in the
// following list will be used (assuming T is defined in namespace
// foo):
//
// 1. foo::PrintTo(const T&, ostream*)
// 2. operator<<(ostream&, const T&) defined in either foo or the
// global namespace.
//
// However if T is an STL-style container then it is printed element-wise
// unless foo::PrintTo(const T&, ostream*) is defined. Note that
// operator<<() is ignored for container types.
//
// If none of the above is defined, it will print the debug string of
// the value if it is a protocol buffer, or print the raw bytes in the
// value otherwise.
//
// To aid debugging: when T is a reference type, the address of the
// value is also printed; when T is a (const) char pointer, both the
// pointer value and the NUL-terminated string it points to are
// printed.
//
// We also provide some convenient wrappers:
//
// // Prints a value to a string. For a (const or not) char
// // pointer, the NUL-terminated string (but not the pointer) is
// // printed.
// std::string ::testing::PrintToString(const T& value);
//
// // Prints a value tersely: for a reference type, the referenced
// // value (but not the address) is printed; for a (const or not) char
// // pointer, the NUL-terminated string (but not the pointer) is
// // printed.
// void ::testing::internal::UniversalTersePrint(const T& value, ostream*);
//
// // Prints value using the type inferred by the compiler. The difference
// // from UniversalTersePrint() is that this function prints both the
// // pointer and the NUL-terminated string for a (const or not) char pointer.
// void ::testing::internal::UniversalPrint(const T& value, ostream*);
//
// // Prints the fields of a tuple tersely to a string vector, one
// // element for each field. Tuple support must be enabled in
// // gtest-port.h.
// std::vector<string> UniversalTersePrintTupleFieldsToStrings(
// const Tuple& value);
//
// Known limitation:
//
// The print primitives print the elements of an STL-style container
// using the compiler-inferred type of *iter where iter is a
// const_iterator of the container. When const_iterator is an input
// iterator but not a forward iterator, this inferred type may not
// match value_type, and the print output may be incorrect. In
// practice, this is rarely a problem as for most containers
// const_iterator is a forward iterator. We'll fix this if there's an
// actual need for it. Note that this fix cannot rely on value_type
// being defined as many user-defined container types don't have
// value_type.
// GOOGLETEST_CM0001 DO NOT DELETE
#ifndef GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
#define GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
#include <ostream> // NOLINT
#include <sstream>
#include <string>
#include <utility>
#include <vector>
#include "gtest/internal/gtest-port.h"
#include "gtest/internal/gtest-internal.h"
#if GTEST_HAS_STD_TUPLE_
# include <tuple>
#endif
#if GTEST_HAS_ABSL
#include "absl/strings/string_view.h"
#include "absl/types/optional.h"
#include "absl/types/variant.h"
#endif // GTEST_HAS_ABSL
namespace testing {
// Definitions in the 'internal' and 'internal2' name spaces are
// subject to change without notice. DO NOT USE THEM IN USER CODE!
namespace internal2 {
// Prints the given number of bytes in the given object to the given
// ostream.
GTEST_API_ void PrintBytesInObjectTo(const unsigned char* obj_bytes,
size_t count,
::std::ostream* os);
// For selecting which printer to use when a given type has neither <<
// nor PrintTo().
enum TypeKind {
kProtobuf, // a protobuf type
kConvertibleToInteger, // a type implicitly convertible to BiggestInt
// (e.g. a named or unnamed enum type)
#if GTEST_HAS_ABSL
kConvertibleToStringView, // a type implicitly convertible to
// absl::string_view
#endif
kOtherType // anything else
};
// TypeWithoutFormatter<T, kTypeKind>::PrintValue(value, os) is called
// by the universal printer to print a value of type T when neither
// operator<< nor PrintTo() is defined for T, where kTypeKind is the
// "kind" of T as defined by enum TypeKind.
template <typename T, TypeKind kTypeKind>
class TypeWithoutFormatter {
public:
// This default version is called when kTypeKind is kOtherType.
static void PrintValue(const T& value, ::std::ostream* os) {
PrintBytesInObjectTo(static_cast<const unsigned char*>(
reinterpret_cast<const void*>(&value)),
sizeof(value), os);
}
};
// We print a protobuf using its ShortDebugString() when the string
// doesn't exceed this many characters; otherwise we print it using
// DebugString() for better readability.
const size_t kProtobufOneLinerMaxLength = 50;
template <typename T>
class TypeWithoutFormatter<T, kProtobuf> {
public:
static void PrintValue(const T& value, ::std::ostream* os) {
std::string pretty_str = value.ShortDebugString();
if (pretty_str.length() > kProtobufOneLinerMaxLength) {
pretty_str = "\n" + value.DebugString();
}
*os << ("<" + pretty_str + ">");
}
};
template <typename T>
class TypeWithoutFormatter<T, kConvertibleToInteger> {
public:
// Since T has no << operator or PrintTo() but can be implicitly
// converted to BiggestInt, we print it as a BiggestInt.
//
// Most likely T is an enum type (either named or unnamed), in which
// case printing it as an integer is the desired behavior. In case
// T is not an enum, printing it as an integer is the best we can do
// given that it has no user-defined printer.
static void PrintValue(const T& value, ::std::ostream* os) {
const internal::BiggestInt kBigInt = value;
*os << kBigInt;
}
};
#if GTEST_HAS_ABSL
template <typename T>
class TypeWithoutFormatter<T, kConvertibleToStringView> {
public:
// Since T has neither operator<< nor PrintTo() but can be implicitly
// converted to absl::string_view, we print it as a absl::string_view.
//
// Note: the implementation is further below, as it depends on
// internal::PrintTo symbol which is defined later in the file.
static void PrintValue(const T& value, ::std::ostream* os);
};
#endif
// Prints the given value to the given ostream. If the value is a
// protocol message, its debug string is printed; if it's an enum or
// of a type implicitly convertible to BiggestInt, it's printed as an
// integer; otherwise the bytes in the value are printed. This is
// what UniversalPrinter<T>::Print() does when it knows nothing about
// type T and T has neither << operator nor PrintTo().
//
// A user can override this behavior for a class type Foo by defining
// a << operator in the namespace where Foo is defined.
//
// We put this operator in namespace 'internal2' instead of 'internal'
// to simplify the implementation, as much code in 'internal' needs to
// use << in STL, which would conflict with our own << were it defined
// in 'internal'.
//
// Note that this operator<< takes a generic std::basic_ostream<Char,
// CharTraits> type instead of the more restricted std::ostream. If
// we define it to take an std::ostream instead, we'll get an
// "ambiguous overloads" compiler error when trying to print a type
// Foo that supports streaming to std::basic_ostream<Char,
// CharTraits>, as the compiler cannot tell whether
// operator<<(std::ostream&, const T&) or
// operator<<(std::basic_stream<Char, CharTraits>, const Foo&) is more
// specific.
template <typename Char, typename CharTraits, typename T>
::std::basic_ostream<Char, CharTraits>& operator<<(
::std::basic_ostream<Char, CharTraits>& os, const T& x) {
TypeWithoutFormatter<T, (internal::IsAProtocolMessage<T>::value
? kProtobuf
: internal::ImplicitlyConvertible<
const T&, internal::BiggestInt>::value
? kConvertibleToInteger
:
#if GTEST_HAS_ABSL
internal::ImplicitlyConvertible<
const T&, absl::string_view>::value
? kConvertibleToStringView
:
#endif
kOtherType)>::PrintValue(x, &os);
return os;
}
} // namespace internal2
} // namespace testing
// This namespace MUST NOT BE NESTED IN ::testing, or the name look-up
// magic needed for implementing UniversalPrinter won't work.
namespace testing_internal {
// Used to print a value that is not an STL-style container when the
// user doesn't define PrintTo() for it.
template <typename T>
void DefaultPrintNonContainerTo(const T& value, ::std::ostream* os) {
// With the following statement, during unqualified name lookup,
// testing::internal2::operator<< appears as if it was declared in
// the nearest enclosing namespace that contains both
// ::testing_internal and ::testing::internal2, i.e. the global
// namespace. For more details, refer to the C++ Standard section
// 7.3.4-1 [namespace.udir]. This allows us to fall back onto
// testing::internal2::operator<< in case T doesn't come with a <<
// operator.
//
// We cannot write 'using ::testing::internal2::operator<<;', which
// gcc 3.3 fails to compile due to a compiler bug.
using namespace ::testing::internal2; // NOLINT
// Assuming T is defined in namespace foo, in the next statement,
// the compiler will consider all of:
//
// 1. foo::operator<< (thanks to Koenig look-up),
// 2. ::operator<< (as the current namespace is enclosed in ::),
// 3. testing::internal2::operator<< (thanks to the using statement above).
//
// The operator<< whose type matches T best will be picked.
//
// We deliberately allow #2 to be a candidate, as sometimes it's
// impossible to define #1 (e.g. when foo is ::std, defining
// anything in it is undefined behavior unless you are a compiler
// vendor.).
*os << value;
}
} // namespace testing_internal
namespace testing {
namespace internal {
// FormatForComparison<ToPrint, OtherOperand>::Format(value) formats a
// value of type ToPrint that is an operand of a comparison assertion
// (e.g. ASSERT_EQ). OtherOperand is the type of the other operand in
// the comparison, and is used to help determine the best way to
// format the value. In particular, when the value is a C string
// (char pointer) and the other operand is an STL string object, we
// want to format the C string as a string, since we know it is
// compared by value with the string object. If the value is a char
// pointer but the other operand is not an STL string object, we don't
// know whether the pointer is supposed to point to a NUL-terminated
// string, and thus want to print it as a pointer to be safe.
//
// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
// The default case.
template <typename ToPrint, typename OtherOperand>
class FormatForComparison {
public:
static ::std::string Format(const ToPrint& value) {
return ::testing::PrintToString(value);
}
};
// Array.
template <typename ToPrint, size_t N, typename OtherOperand>
class FormatForComparison<ToPrint[N], OtherOperand> {
public:
static ::std::string Format(const ToPrint* value) {
return FormatForComparison<const ToPrint*, OtherOperand>::Format(value);
}
};
// By default, print C string as pointers to be safe, as we don't know
// whether they actually point to a NUL-terminated string.
#define GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(CharType) \
template <typename OtherOperand> \
class FormatForComparison<CharType*, OtherOperand> { \
public: \
static ::std::string Format(CharType* value) { \
return ::testing::PrintToString(static_cast<const void*>(value)); \
} \
}
GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(char);
GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const char);
GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(wchar_t);
GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_(const wchar_t);
#undef GTEST_IMPL_FORMAT_C_STRING_AS_POINTER_
// If a C string is compared with an STL string object, we know it's meant
// to point to a NUL-terminated string, and thus can print it as a string.
#define GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(CharType, OtherStringType) \
template <> \
class FormatForComparison<CharType*, OtherStringType> { \
public: \
static ::std::string Format(CharType* value) { \
return ::testing::PrintToString(value); \
} \
}
GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::std::string);
GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::std::string);
#if GTEST_HAS_GLOBAL_STRING
GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(char, ::string);
GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const char, ::string);
#endif
#if GTEST_HAS_GLOBAL_WSTRING
GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(wchar_t, ::wstring);
GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const wchar_t, ::wstring);
#endif
#if GTEST_HAS_STD_WSTRING
GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(wchar_t, ::std::wstring);
GTEST_IMPL_FORMAT_C_STRING_AS_STRING_(const wchar_t, ::std::wstring);
#endif
#undef GTEST_IMPL_FORMAT_C_STRING_AS_STRING_
// Formats a comparison assertion (e.g. ASSERT_EQ, EXPECT_LT, and etc)
// operand to be used in a failure message. The type (but not value)
// of the other operand may affect the format. This allows us to
// print a char* as a raw pointer when it is compared against another
// char* or void*, and print it as a C string when it is compared
// against an std::string object, for example.
//
// INTERNAL IMPLEMENTATION - DO NOT USE IN A USER PROGRAM.
template <typename T1, typename T2>
std::string FormatForComparisonFailureMessage(
const T1& value, const T2& /* other_operand */) {
return FormatForComparison<T1, T2>::Format(value);
}
// UniversalPrinter<T>::Print(value, ostream_ptr) prints the given
// value to the given ostream. The caller must ensure that
// 'ostream_ptr' is not NULL, or the behavior is undefined.
//
// We define UniversalPrinter as a class template (as opposed to a
// function template), as we need to partially specialize it for
// reference types, which cannot be done with function templates.
template <typename T>
class UniversalPrinter;
template <typename T>
void UniversalPrint(const T& value, ::std::ostream* os);
enum DefaultPrinterType {
kPrintContainer,
kPrintPointer,
kPrintFunctionPointer,
kPrintOther,
};
template <DefaultPrinterType type> struct WrapPrinterType {};
// Used to print an STL-style container when the user doesn't define
// a PrintTo() for it.
template <typename C>
void DefaultPrintTo(WrapPrinterType<kPrintContainer> /* dummy */,
const C& container, ::std::ostream* os) {
const size_t kMaxCount = 32; // The maximum number of elements to print.
*os << '{';
size_t count = 0;
for (typename C::const_iterator it = container.begin();
it != container.end(); ++it, ++count) {
if (count > 0) {
*os << ',';
if (count == kMaxCount) { // Enough has been printed.
*os << " ...";
break;
}
}
*os << ' ';
// We cannot call PrintTo(*it, os) here as PrintTo() doesn't
// handle *it being a native array.
internal::UniversalPrint(*it, os);
}
if (count > 0) {
*os << ' ';
}
*os << '}';
}
// Used to print a pointer that is neither a char pointer nor a member
// pointer, when the user doesn't define PrintTo() for it. (A member
// variable pointer or member function pointer doesn't really point to
// a location in the address space. Their representation is
// implementation-defined. Therefore they will be printed as raw
// bytes.)
template <typename T>
void DefaultPrintTo(WrapPrinterType<kPrintPointer> /* dummy */,
T* p, ::std::ostream* os) {
if (p == NULL) {
*os << "NULL";
} else {
// T is not a function type. We just call << to print p,
// relying on ADL to pick up user-defined << for their pointer
// types, if any.
*os << p;
}
}
template <typename T>
void DefaultPrintTo(WrapPrinterType<kPrintFunctionPointer> /* dummy */,
T* p, ::std::ostream* os) {
if (p == NULL) {
*os << "NULL";
} else {
// T is a function type, so '*os << p' doesn't do what we want
// (it just prints p as bool). We want to print p as a const
// void*.
*os << reinterpret_cast<const void*>(p);
}
}
// Used to print a non-container, non-pointer value when the user
// doesn't define PrintTo() for it.
template <typename T>
void DefaultPrintTo(WrapPrinterType<kPrintOther> /* dummy */,
const T& value, ::std::ostream* os) {
::testing_internal::DefaultPrintNonContainerTo(value, os);
}
// Prints the given value using the << operator if it has one;
// otherwise prints the bytes in it. This is what
// UniversalPrinter<T>::Print() does when PrintTo() is not specialized
// or overloaded for type T.
//
// A user can override this behavior for a class type Foo by defining
// an overload of PrintTo() in the namespace where Foo is defined. We
// give the user this option as sometimes defining a << operator for
// Foo is not desirable (e.g. the coding style may prevent doing it,
// or there is already a << operator but it doesn't do what the user
// wants).
template <typename T>
void PrintTo(const T& value, ::std::ostream* os) {
// DefaultPrintTo() is overloaded. The type of its first argument
// determines which version will be picked.
//
// Note that we check for container types here, prior to we check
// for protocol message types in our operator<<. The rationale is:
//
// For protocol messages, we want to give people a chance to
// override Google Mock's format by defining a PrintTo() or
// operator<<. For STL containers, other formats can be
// incompatible with Google Mock's format for the container
// elements; therefore we check for container types here to ensure
// that our format is used.
//
// Note that MSVC and clang-cl do allow an implicit conversion from
// pointer-to-function to pointer-to-object, but clang-cl warns on it.
// So don't use ImplicitlyConvertible if it can be helped since it will
// cause this warning, and use a separate overload of DefaultPrintTo for
// function pointers so that the `*os << p` in the object pointer overload
// doesn't cause that warning either.
DefaultPrintTo(
WrapPrinterType <
(sizeof(IsContainerTest<T>(0)) == sizeof(IsContainer)) &&
!IsRecursiveContainer<T>::value
? kPrintContainer
: !is_pointer<T>::value
? kPrintOther
#if GTEST_LANG_CXX11
: std::is_function<typename std::remove_pointer<T>::type>::value
#else
: !internal::ImplicitlyConvertible<T, const void*>::value
#endif
? kPrintFunctionPointer
: kPrintPointer > (),
value, os);
}
// The following list of PrintTo() overloads tells
// UniversalPrinter<T>::Print() how to print standard types (built-in
// types, strings, plain arrays, and pointers).
// Overloads for various char types.
GTEST_API_ void PrintTo(unsigned char c, ::std::ostream* os);
GTEST_API_ void PrintTo(signed char c, ::std::ostream* os);
inline void PrintTo(char c, ::std::ostream* os) {
// When printing a plain char, we always treat it as unsigned. This
// way, the output won't be affected by whether the compiler thinks
// char is signed or not.
PrintTo(static_cast<unsigned char>(c), os);
}
// Overloads for other simple built-in types.
inline void PrintTo(bool x, ::std::ostream* os) {
*os << (x ? "true" : "false");
}
// Overload for wchar_t type.
// Prints a wchar_t as a symbol if it is printable or as its internal
// code otherwise and also as its decimal code (except for L'\0').
// The L'\0' char is printed as "L'\\0'". The decimal code is printed
// as signed integer when wchar_t is implemented by the compiler
// as a signed type and is printed as an unsigned integer when wchar_t
// is implemented as an unsigned type.
GTEST_API_ void PrintTo(wchar_t wc, ::std::ostream* os);
// Overloads for C strings.
GTEST_API_ void PrintTo(const char* s, ::std::ostream* os);
inline void PrintTo(char* s, ::std::ostream* os) {
PrintTo(ImplicitCast_<const char*>(s), os);
}
// signed/unsigned char is often used for representing binary data, so
// we print pointers to it as void* to be safe.
inline void PrintTo(const signed char* s, ::std::ostream* os) {
PrintTo(ImplicitCast_<const void*>(s), os);
}
inline void PrintTo(signed char* s, ::std::ostream* os) {
PrintTo(ImplicitCast_<const void*>(s), os);
}
inline void PrintTo(const unsigned char* s, ::std::ostream* os) {
PrintTo(ImplicitCast_<const void*>(s), os);
}
inline void PrintTo(unsigned char* s, ::std::ostream* os) {
PrintTo(ImplicitCast_<const void*>(s), os);
}
// MSVC can be configured to define wchar_t as a typedef of unsigned
// short. It defines _NATIVE_WCHAR_T_DEFINED when wchar_t is a native
// type. When wchar_t is a typedef, defining an overload for const
// wchar_t* would cause unsigned short* be printed as a wide string,
// possibly causing invalid memory accesses.
#if !defined(_MSC_VER) || defined(_NATIVE_WCHAR_T_DEFINED)
// Overloads for wide C strings
GTEST_API_ void PrintTo(const wchar_t* s, ::std::ostream* os);
inline void PrintTo(wchar_t* s, ::std::ostream* os) {
PrintTo(ImplicitCast_<const wchar_t*>(s), os);
}
#endif
// Overload for C arrays. Multi-dimensional arrays are printed
// properly.
// Prints the given number of elements in an array, without printing
// the curly braces.
template <typename T>
void PrintRawArrayTo(const T a[], size_t count, ::std::ostream* os) {
UniversalPrint(a[0], os);
for (size_t i = 1; i != count; i++) {
*os << ", ";
UniversalPrint(a[i], os);
}
}
// Overloads for ::string and ::std::string.
#if GTEST_HAS_GLOBAL_STRING
GTEST_API_ void PrintStringTo(const ::string&s, ::std::ostream* os);
inline void PrintTo(const ::string& s, ::std::ostream* os) {
PrintStringTo(s, os);
}
#endif // GTEST_HAS_GLOBAL_STRING
GTEST_API_ void PrintStringTo(const ::std::string&s, ::std::ostream* os);
inline void PrintTo(const ::std::string& s, ::std::ostream* os) {
PrintStringTo(s, os);
}
// Overloads for ::wstring and ::std::wstring.
#if GTEST_HAS_GLOBAL_WSTRING
GTEST_API_ void PrintWideStringTo(const ::wstring&s, ::std::ostream* os);
inline void PrintTo(const ::wstring& s, ::std::ostream* os) {
PrintWideStringTo(s, os);
}
#endif // GTEST_HAS_GLOBAL_WSTRING
#if GTEST_HAS_STD_WSTRING
GTEST_API_ void PrintWideStringTo(const ::std::wstring&s, ::std::ostream* os);
inline void PrintTo(const ::std::wstring& s, ::std::ostream* os) {
PrintWideStringTo(s, os);
}
#endif // GTEST_HAS_STD_WSTRING
#if GTEST_HAS_ABSL
// Overload for absl::string_view.
inline void PrintTo(absl::string_view sp, ::std::ostream* os) {
PrintTo(::std::string(sp), os);
}
#endif // GTEST_HAS_ABSL
#if GTEST_LANG_CXX11
inline void PrintTo(std::nullptr_t, ::std::ostream* os) { *os << "(nullptr)"; }
#endif // GTEST_LANG_CXX11
#if GTEST_HAS_TR1_TUPLE || GTEST_HAS_STD_TUPLE_
// Helper function for printing a tuple. T must be instantiated with
// a tuple type.
template <typename T>
void PrintTupleTo(const T& t, ::std::ostream* os);
#endif // GTEST_HAS_TR1_TUPLE || GTEST_HAS_STD_TUPLE_
#if GTEST_HAS_TR1_TUPLE
// Overload for ::std::tr1::tuple. Needed for printing function arguments,
// which are packed as tuples.
// Overloaded PrintTo() for tuples of various arities. We support
// tuples of up-to 10 fields. The following implementation works
// regardless of whether tr1::tuple is implemented using the
// non-standard variadic template feature or not.
inline void PrintTo(const ::std::tr1::tuple<>& t, ::std::ostream* os) {
PrintTupleTo(t, os);
}
template <typename T1>
void PrintTo(const ::std::tr1::tuple<T1>& t, ::std::ostream* os) {
PrintTupleTo(t, os);
}
template <typename T1, typename T2>
void PrintTo(const ::std::tr1::tuple<T1, T2>& t, ::std::ostream* os) {
PrintTupleTo(t, os);
}
template <typename T1, typename T2, typename T3>
void PrintTo(const ::std::tr1::tuple<T1, T2, T3>& t, ::std::ostream* os) {
PrintTupleTo(t, os);
}
template <typename T1, typename T2, typename T3, typename T4>
void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4>& t, ::std::ostream* os) {
PrintTupleTo(t, os);
}
template <typename T1, typename T2, typename T3, typename T4, typename T5>
void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5>& t,
::std::ostream* os) {
PrintTupleTo(t, os);
}
template <typename T1, typename T2, typename T3, typename T4, typename T5,
typename T6>
void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6>& t,
::std::ostream* os) {
PrintTupleTo(t, os);
}
template <typename T1, typename T2, typename T3, typename T4, typename T5,
typename T6, typename T7>
void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6, T7>& t,
::std::ostream* os) {
PrintTupleTo(t, os);
}
template <typename T1, typename T2, typename T3, typename T4, typename T5,
typename T6, typename T7, typename T8>
void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6, T7, T8>& t,
::std::ostream* os) {
PrintTupleTo(t, os);
}
template <typename T1, typename T2, typename T3, typename T4, typename T5,
typename T6, typename T7, typename T8, typename T9>
void PrintTo(const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9>& t,
::std::ostream* os) {
PrintTupleTo(t, os);
}
template <typename T1, typename T2, typename T3, typename T4, typename T5,
typename T6, typename T7, typename T8, typename T9, typename T10>
void PrintTo(
const ::std::tr1::tuple<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>& t,
::std::ostream* os) {
PrintTupleTo(t, os);
}
#endif // GTEST_HAS_TR1_TUPLE
#if GTEST_HAS_STD_TUPLE_
template <typename... Types>
void PrintTo(const ::std::tuple<Types...>& t, ::std::ostream* os) {
PrintTupleTo(t, os);
}
#endif // GTEST_HAS_STD_TUPLE_
// Overload for std::pair.
template <typename T1, typename T2>
void PrintTo(const ::std::pair<T1, T2>& value, ::std::ostream* os) {
*os << '(';
// We cannot use UniversalPrint(value.first, os) here, as T1 may be
// a reference type. The same for printing value.second.
UniversalPrinter<T1>::Print(value.first, os);
*os << ", ";
UniversalPrinter<T2>::Print(value.second, os);
*os << ')';
}
// Implements printing a non-reference type T by letting the compiler
// pick the right overload of PrintTo() for T.
template <typename T>
class UniversalPrinter {
public:
// MSVC warns about adding const to a function type, so we want to
// disable the warning.
GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
// Note: we deliberately don't call this PrintTo(), as that name
// conflicts with ::testing::internal::PrintTo in the body of the
// function.
static void Print(const T& value, ::std::ostream* os) {
// By default, ::testing::internal::PrintTo() is used for printing
// the value.
//
// Thanks to Koenig look-up, if T is a class and has its own
// PrintTo() function defined in its namespace, that function will
// be visible here. Since it is more specific than the generic ones
// in ::testing::internal, it will be picked by the compiler in the
// following statement - exactly what we want.
PrintTo(value, os);
}
GTEST_DISABLE_MSC_WARNINGS_POP_()
};
#if GTEST_HAS_ABSL
// Printer for absl::optional
template <typename T>
class UniversalPrinter<::absl::optional<T>> {
public:
static void Print(const ::absl::optional<T>& value, ::std::ostream* os) {
*os << '(';
if (!value) {
*os << "nullopt";
} else {
UniversalPrint(*value, os);
}
*os << ')';
}
};
// Printer for absl::variant
template <typename... T>
class UniversalPrinter<::absl::variant<T...>> {
public:
static void Print(const ::absl::variant<T...>& value, ::std::ostream* os) {
*os << '(';
absl::visit(Visitor{os}, value);
*os << ')';
}
private:
struct Visitor {
template <typename U>
void operator()(const U& u) const {
*os << "'" << GetTypeName<U>() << "' with value ";
UniversalPrint(u, os);
}
::std::ostream* os;
};
};
#endif // GTEST_HAS_ABSL
// UniversalPrintArray(begin, len, os) prints an array of 'len'
// elements, starting at address 'begin'.
template <typename T>
void UniversalPrintArray(const T* begin, size_t len, ::std::ostream* os) {
if (len == 0) {
*os << "{}";
} else {
*os << "{ ";
const size_t kThreshold = 18;
const size_t kChunkSize = 8;
// If the array has more than kThreshold elements, we'll have to
// omit some details by printing only the first and the last
// kChunkSize elements.
// FIXME: let the user control the threshold using a flag.
if (len <= kThreshold) {
PrintRawArrayTo(begin, len, os);
} else {
PrintRawArrayTo(begin, kChunkSize, os);
*os << ", ..., ";
PrintRawArrayTo(begin + len - kChunkSize, kChunkSize, os);
}
*os << " }";
}
}
// This overload prints a (const) char array compactly.
GTEST_API_ void UniversalPrintArray(
const char* begin, size_t len, ::std::ostream* os);
// This overload prints a (const) wchar_t array compactly.
GTEST_API_ void UniversalPrintArray(
const wchar_t* begin, size_t len, ::std::ostream* os);
// Implements printing an array type T[N].
template <typename T, size_t N>
class UniversalPrinter<T[N]> {
public:
// Prints the given array, omitting some elements when there are too
// many.
static void Print(const T (&a)[N], ::std::ostream* os) {
UniversalPrintArray(a, N, os);
}
};
// Implements printing a reference type T&.
template <typename T>
class UniversalPrinter<T&> {
public:
// MSVC warns about adding const to a function type, so we want to
// disable the warning.
GTEST_DISABLE_MSC_WARNINGS_PUSH_(4180)
static void Print(const T& value, ::std::ostream* os) {
// Prints the address of the value. We use reinterpret_cast here
// as static_cast doesn't compile when T is a function type.
*os << "@" << reinterpret_cast<const void*>(&value) << " ";
// Then prints the value itself.
UniversalPrint(value, os);
}
GTEST_DISABLE_MSC_WARNINGS_POP_()
};
// Prints a value tersely: for a reference type, the referenced value
// (but not the address) is printed; for a (const) char pointer, the
// NUL-terminated string (but not the pointer) is printed.
template <typename T>
class UniversalTersePrinter {
public:
static void Print(const T& value, ::std::ostream* os) {
UniversalPrint(value, os);
}
};
template <typename T>
class UniversalTersePrinter<T&> {
public:
static void Print(const T& value, ::std::ostream* os) {
UniversalPrint(value, os);
}
};
template <typename T, size_t N>
class UniversalTersePrinter<T[N]> {
public:
static void Print(const T (&value)[N], ::std::ostream* os) {
UniversalPrinter<T[N]>::Print(value, os);
}
};
template <>
class UniversalTersePrinter<const char*> {
public:
static void Print(const char* str, ::std::ostream* os) {
if (str == NULL) {
*os << "NULL";
} else {
UniversalPrint(std::string(str), os);
}
}
};
template <>
class UniversalTersePrinter<char*> {
public:
static void Print(char* str, ::std::ostream* os) {
UniversalTersePrinter<const char*>::Print(str, os);
}
};
#if GTEST_HAS_STD_WSTRING
template <>
class UniversalTersePrinter<const wchar_t*> {
public:
static void Print(const wchar_t* str, ::std::ostream* os) {
if (str == NULL) {
*os << "NULL";
} else {
UniversalPrint(::std::wstring(str), os);
}
}
};
#endif
template <>
class UniversalTersePrinter<wchar_t*> {
public:
static void Print(wchar_t* str, ::std::ostream* os) {
UniversalTersePrinter<const wchar_t*>::Print(str, os);
}
};
template <typename T>
void UniversalTersePrint(const T& value, ::std::ostream* os) {
UniversalTersePrinter<T>::Print(value, os);
}
// Prints a value using the type inferred by the compiler. The
// difference between this and UniversalTersePrint() is that for a
// (const) char pointer, this prints both the pointer and the
// NUL-terminated string.
template <typename T>
void UniversalPrint(const T& value, ::std::ostream* os) {
// A workarond for the bug in VC++ 7.1 that prevents us from instantiating
// UniversalPrinter with T directly.
typedef T T1;
UniversalPrinter<T1>::Print(value, os);
}
typedef ::std::vector< ::std::string> Strings;
// TuplePolicy<TupleT> must provide:
// - tuple_size
// size of tuple TupleT.
// - get<size_t I>(const TupleT& t)
// static function extracting element I of tuple TupleT.
// - tuple_element<size_t I>::type
// type of element I of tuple TupleT.
template <typename TupleT>
struct TuplePolicy;
#if GTEST_HAS_TR1_TUPLE
template <typename TupleT>
struct TuplePolicy {
typedef TupleT Tuple;
static const size_t tuple_size = ::std::tr1::tuple_size<Tuple>::value;
template <size_t I>
struct tuple_element : ::std::tr1::tuple_element<static_cast<int>(I), Tuple> {
};
template <size_t I>
static typename AddReference<const typename ::std::tr1::tuple_element<
static_cast<int>(I), Tuple>::type>::type
get(const Tuple& tuple) {
return ::std::tr1::get<I>(tuple);
}
};
template <typename TupleT>
const size_t TuplePolicy<TupleT>::tuple_size;
#endif // GTEST_HAS_TR1_TUPLE
#if GTEST_HAS_STD_TUPLE_
template <typename... Types>
struct TuplePolicy< ::std::tuple<Types...> > {
typedef ::std::tuple<Types...> Tuple;
static const size_t tuple_size = ::std::tuple_size<Tuple>::value;
template <size_t I>
struct tuple_element : ::std::tuple_element<I, Tuple> {};
template <size_t I>
static const typename ::std::tuple_element<I, Tuple>::type& get(
const Tuple& tuple) {
return ::std::get<I>(tuple);
}
};
template <typename... Types>
const size_t TuplePolicy< ::std::tuple<Types...> >::tuple_size;
#endif // GTEST_HAS_STD_TUPLE_
#if GTEST_HAS_TR1_TUPLE || GTEST_HAS_STD_TUPLE_
// This helper template allows PrintTo() for tuples and
// UniversalTersePrintTupleFieldsToStrings() to be defined by
// induction on the number of tuple fields. The idea is that
// TuplePrefixPrinter<N>::PrintPrefixTo(t, os) prints the first N
// fields in tuple t, and can be defined in terms of
// TuplePrefixPrinter<N - 1>.
//
// The inductive case.
template <size_t N>
struct TuplePrefixPrinter {
// Prints the first N fields of a tuple.
template <typename Tuple>
static void PrintPrefixTo(const Tuple& t, ::std::ostream* os) {
TuplePrefixPrinter<N - 1>::PrintPrefixTo(t, os);
GTEST_INTENTIONAL_CONST_COND_PUSH_()
if (N > 1) {
GTEST_INTENTIONAL_CONST_COND_POP_()
*os << ", ";
}
UniversalPrinter<
typename TuplePolicy<Tuple>::template tuple_element<N - 1>::type>
::Print(TuplePolicy<Tuple>::template get<N - 1>(t), os);
}
// Tersely prints the first N fields of a tuple to a string vector,
// one element for each field.
template <typename Tuple>
static void TersePrintPrefixToStrings(const Tuple& t, Strings* strings) {
TuplePrefixPrinter<N - 1>::TersePrintPrefixToStrings(t, strings);
::std::stringstream ss;
UniversalTersePrint(TuplePolicy<Tuple>::template get<N - 1>(t), &ss);
strings->push_back(ss.str());
}
};
// Base case.
template <>
struct TuplePrefixPrinter<0> {
template <typename Tuple>
static void PrintPrefixTo(const Tuple&, ::std::ostream*) {}
template <typename Tuple>
static void TersePrintPrefixToStrings(const Tuple&, Strings*) {}
};
// Helper function for printing a tuple.
// Tuple must be either std::tr1::tuple or std::tuple type.
template <typename Tuple>
void PrintTupleTo(const Tuple& t, ::std::ostream* os) {
*os << "(";
TuplePrefixPrinter<TuplePolicy<Tuple>::tuple_size>::PrintPrefixTo(t, os);
*os << ")";
}
// Prints the fields of a tuple tersely to a string vector, one
// element for each field. See the comment before
// UniversalTersePrint() for how we define "tersely".
template <typename Tuple>
Strings UniversalTersePrintTupleFieldsToStrings(const Tuple& value) {
Strings result;
TuplePrefixPrinter<TuplePolicy<Tuple>::tuple_size>::
TersePrintPrefixToStrings(value, &result);
return result;
}
#endif // GTEST_HAS_TR1_TUPLE || GTEST_HAS_STD_TUPLE_
} // namespace internal
#if GTEST_HAS_ABSL
namespace internal2 {
template <typename T>
void TypeWithoutFormatter<T, kConvertibleToStringView>::PrintValue(
const T& value, ::std::ostream* os) {
internal::PrintTo(absl::string_view(value), os);
}
} // namespace internal2
#endif
template <typename T>
::std::string PrintToString(const T& value) {
::std::stringstream ss;
internal::UniversalTersePrinter<T>::Print(value, &ss);
return ss.str();
}
} // namespace testing
// Include any custom printer added by the local installation.
// We must include this header at the end to make sure it can use the
// declarations from this file.
#include "gtest/internal/custom/gtest-printers.h"
#endif // GTEST_INCLUDE_GTEST_GTEST_PRINTERS_H_