diff options
Diffstat (limited to 'absl/types/internal/conformance_testing_helpers.h')
| -rw-r--r-- | absl/types/internal/conformance_testing_helpers.h | 391 |
1 files changed, 391 insertions, 0 deletions
diff --git a/absl/types/internal/conformance_testing_helpers.h b/absl/types/internal/conformance_testing_helpers.h new file mode 100644 index 00000000..00775f96 --- /dev/null +++ b/absl/types/internal/conformance_testing_helpers.h @@ -0,0 +1,391 @@ +// Copyright 2019 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#ifndef ABSL_TYPES_INTERNAL_CONFORMANCE_TESTING_HELPERS_H_ +#define ABSL_TYPES_INTERNAL_CONFORMANCE_TESTING_HELPERS_H_ + +// Checks to determine whether or not we can use abi::__cxa_demangle +#if (defined(__ANDROID__) || defined(ANDROID)) && !defined(OS_ANDROID) +#define ABSL_INTERNAL_OS_ANDROID +#endif + +// We support certain compilers only. See demangle.h for details. +#if defined(OS_ANDROID) && (defined(__i386__) || defined(__x86_64__)) +#define ABSL_TYPES_INTERNAL_HAS_CXA_DEMANGLE 0 +#elif (__GNUC__ >= 4 || (__GNUC__ >= 3 && __GNUC_MINOR__ >= 4)) && \ + !defined(__mips__) +#define ABSL_TYPES_INTERNAL_HAS_CXA_DEMANGLE 1 +#elif defined(__clang__) && !defined(_MSC_VER) +#define ABSL_TYPES_INTERNAL_HAS_CXA_DEMANGLE 1 +#else +#define ABSL_TYPES_INTERNAL_HAS_CXA_DEMANGLE 0 +#endif + +#include <tuple> +#include <type_traits> +#include <utility> + +#include "absl/meta/type_traits.h" +#include "absl/strings/string_view.h" +#include "absl/utility/utility.h" + +#if ABSL_TYPES_INTERNAL_HAS_CXA_DEMANGLE +#include <cxxabi.h> + +#include <cstdlib> +#endif + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace types_internal { + +// Return a readable name for type T. +template <class T> +absl::string_view NameOfImpl() { +// TODO(calabrese) Investigate using debugging:internal_demangle as a fallback. +#if ABSL_TYPES_INTERNAL_HAS_CXA_DEMANGLE + int status = 0; + char* demangled_name = nullptr; + + demangled_name = + abi::__cxa_demangle(typeid(T).name(), nullptr, nullptr, &status); + + if (status == 0 && demangled_name != nullptr) { + return demangled_name; + } else { + return typeid(T).name(); + } +#else + return typeid(T).name(); +#endif + // NOTE: We intentionally leak demangled_name so that it remains valid + // throughout the remainder of the program. +} + +// Given a type, returns as nice of a type name as we can produce (demangled). +// +// Note: This currently strips cv-qualifiers and references, but that is okay +// because we only use this internally with unqualified object types. +template <class T> +std::string NameOf() { + static const absl::string_view result = NameOfImpl<T>(); + return std::string(result); +} + +//////////////////////////////////////////////////////////////////////////////// +// +// Metafunction to check if a type is callable with no explicit arguments +template <class Fun, class /*Enabler*/ = void> +struct IsNullaryCallableImpl : std::false_type {}; + +template <class Fun> +struct IsNullaryCallableImpl< + Fun, absl::void_t<decltype(std::declval<const Fun&>()())>> + : std::true_type { + using result_type = decltype(std::declval<const Fun&>()()); + + template <class ValueType> + using for_type = std::is_same<ValueType, result_type>; + + using void_if_true = void; +}; + +template <class Fun> +struct IsNullaryCallable : IsNullaryCallableImpl<Fun> {}; +// +//////////////////////////////////////////////////////////////////////////////// + +// A type that contains a function object that returns an instance of a type +// that is undergoing conformance testing. This function is required to always +// return the same value upon invocation. +template <class Fun> +struct GeneratorType; + +// A type that contains a tuple of GeneratorType<Fun> where each Fun has the +// same return type. The result of each of the different generators should all +// be equal values, though the underlying object representation may differ (such +// as if one returns 0.0 and another return -0.0, or if one returns an empty +// vector and another returns an empty vector with a different capacity. +template <class... Funs> +struct EquivalenceClassType; + +//////////////////////////////////////////////////////////////////////////////// +// +// A metafunction to check if a type is a specialization of EquivalenceClassType +template <class T> +struct IsEquivalenceClass : std::false_type {}; + +template <> +struct IsEquivalenceClass<EquivalenceClassType<>> : std::true_type { + using self = IsEquivalenceClass; + + // A metafunction to check if this EquivalenceClassType is a valid + // EquivalenceClassType for a type `ValueType` that is undergoing testing + template <class ValueType> + using for_type = std::true_type; +}; + +template <class Head, class... Tail> +struct IsEquivalenceClass<EquivalenceClassType<Head, Tail...>> + : std::true_type { + using self = IsEquivalenceClass; + + // The type undergoing conformance testing that this EquivalenceClass + // corresponds to + using result_type = typename IsNullaryCallable<Head>::result_type; + + // A metafunction to check if this EquivalenceClassType is a valid + // EquivalenceClassType for a type `ValueType` that is undergoing testing + template <class ValueType> + using for_type = std::is_same<ValueType, result_type>; +}; +// +//////////////////////////////////////////////////////////////////////////////// + +// A type that contains an ordered series of EquivalenceClassTypes, where the +// the function object of each underlying GeneratorType has the same return type +// +// These equivalence classes are required to be in a logical ascending order +// that is consistent with comparison operators that are defined for the return +// type of each GeneratorType, if any. +template <class... EqClasses> +struct OrderedEquivalenceClasses; + +//////////////////////////////////////////////////////////////////////////////// +// +// A metafunction to determine the return type of the function object contained +// in a GeneratorType specialization. +template <class T> +struct ResultOfGenerator {}; + +template <class Fun> +struct ResultOfGenerator<GeneratorType<Fun>> { + using type = decltype(std::declval<const Fun&>()()); +}; + +template <class Fun> +using ResultOfGeneratorT = typename ResultOfGenerator<GeneratorType<Fun>>::type; +// +//////////////////////////////////////////////////////////////////////////////// + +//////////////////////////////////////////////////////////////////////////////// +// +// A metafunction that yields true iff each of Funs is a GeneratorType +// specialization and they all contain functions with the same return type +template <class /*Enabler*/, class... Funs> +struct AreGeneratorsWithTheSameReturnTypeImpl : std::false_type {}; + +template <> +struct AreGeneratorsWithTheSameReturnTypeImpl<void> : std::true_type {}; + +template <class Head, class... Tail> +struct AreGeneratorsWithTheSameReturnTypeImpl< + typename std::enable_if<absl::conjunction<std::is_same< + ResultOfGeneratorT<Head>, ResultOfGeneratorT<Tail>>...>::value>::type, + Head, Tail...> : std::true_type {}; + +template <class... Funs> +struct AreGeneratorsWithTheSameReturnType + : AreGeneratorsWithTheSameReturnTypeImpl<void, Funs...>::type {}; +// +//////////////////////////////////////////////////////////////////////////////// + +//////////////////////////////////////////////////////////////////////////////// +// +// A metafunction that yields true iff each of Funs is an EquivalenceClassType +// specialization and they all contain GeneratorType specializations that have +// the same return type +template <class... EqClasses> +struct AreEquivalenceClassesOfTheSameType { + static_assert(sizeof...(EqClasses) != sizeof...(EqClasses), ""); +}; + +template <> +struct AreEquivalenceClassesOfTheSameType<> : std::true_type { + using self = AreEquivalenceClassesOfTheSameType; + + // Metafunction to check that a type is the same as all of the equivalence + // classes, if any. + // Note: In this specialization there are no equivalence classes, so the + // value type is always compatible. + template <class /*ValueType*/> + using for_type = std::true_type; +}; + +template <class... Funs> +struct AreEquivalenceClassesOfTheSameType<EquivalenceClassType<Funs...>> + : std::true_type { + using self = AreEquivalenceClassesOfTheSameType; + + // Metafunction to check that a type is the same as all of the equivalence + // classes, if any. + template <class ValueType> + using for_type = typename IsEquivalenceClass< + EquivalenceClassType<Funs...>>::template for_type<ValueType>; +}; + +template <class... TailEqClasses> +struct AreEquivalenceClassesOfTheSameType< + EquivalenceClassType<>, EquivalenceClassType<>, TailEqClasses...> + : AreEquivalenceClassesOfTheSameType<TailEqClasses...>::self {}; + +template <class HeadNextFun, class... TailNextFuns, class... TailEqClasses> +struct AreEquivalenceClassesOfTheSameType< + EquivalenceClassType<>, EquivalenceClassType<HeadNextFun, TailNextFuns...>, + TailEqClasses...> + : AreEquivalenceClassesOfTheSameType< + EquivalenceClassType<HeadNextFun, TailNextFuns...>, + TailEqClasses...>::self {}; + +template <class HeadHeadFun, class... TailHeadFuns, class... TailEqClasses> +struct AreEquivalenceClassesOfTheSameType< + EquivalenceClassType<HeadHeadFun, TailHeadFuns...>, EquivalenceClassType<>, + TailEqClasses...> + : AreEquivalenceClassesOfTheSameType< + EquivalenceClassType<HeadHeadFun, TailHeadFuns...>, + TailEqClasses...>::self {}; + +template <class HeadHeadFun, class... TailHeadFuns, class HeadNextFun, + class... TailNextFuns, class... TailEqClasses> +struct AreEquivalenceClassesOfTheSameType< + EquivalenceClassType<HeadHeadFun, TailHeadFuns...>, + EquivalenceClassType<HeadNextFun, TailNextFuns...>, TailEqClasses...> + : absl::conditional_t< + IsNullaryCallable<HeadNextFun>::template for_type< + typename IsNullaryCallable<HeadHeadFun>::result_type>::value, + AreEquivalenceClassesOfTheSameType< + EquivalenceClassType<HeadHeadFun, TailHeadFuns...>, + TailEqClasses...>, + std::false_type> {}; +// +//////////////////////////////////////////////////////////////////////////////// + +// Execute a function for each passed-in parameter. +template <class Fun, class... Cases> +void ForEachParameter(const Fun& fun, const Cases&... cases) { + const std::initializer_list<bool> results = { + (static_cast<void>(fun(cases)), true)...}; + + (void)results; +} + +// Execute a function on each passed-in parameter (using a bound function). +template <class Fun> +struct ForEachParameterFun { + template <class... T> + void operator()(const T&... cases) const { + (ForEachParameter)(fun, cases...); + } + + Fun fun; +}; + +// Execute a function on each element of a tuple. +template <class Fun, class Tup> +void ForEachTupleElement(const Fun& fun, const Tup& tup) { + absl::apply(ForEachParameterFun<Fun>{fun}, tup); +} + +//////////////////////////////////////////////////////////////////////////////// +// +// Execute a function for each combination of two elements of a tuple, including +// combinations of an element with itself. +template <class Fun, class... T> +struct ForEveryTwoImpl { + template <class Lhs> + struct WithBoundLhs { + template <class Rhs> + void operator()(const Rhs& rhs) const { + fun(lhs, rhs); + } + + Fun fun; + Lhs lhs; + }; + + template <class Lhs> + void operator()(const Lhs& lhs) const { + (ForEachTupleElement)(WithBoundLhs<Lhs>{fun, lhs}, args); + } + + Fun fun; + std::tuple<T...> args; +}; + +template <class Fun, class... T> +void ForEveryTwo(const Fun& fun, std::tuple<T...> args) { + (ForEachTupleElement)(ForEveryTwoImpl<Fun, T...>{fun, args}, args); +} +// +//////////////////////////////////////////////////////////////////////////////// + +//////////////////////////////////////////////////////////////////////////////// +// +// Insert all values into an associative container +template<class Container> +void InsertEach(Container* cont) { +} + +template<class Container, class H, class... T> +void InsertEach(Container* cont, H&& head, T&&... tail) { + cont->insert(head); + (InsertEach)(cont, tail...); +} +// +//////////////////////////////////////////////////////////////////////////////// +// A template with a nested "Invoke" static-member-function that executes a +// passed-in Callable when `Condition` is true, otherwise it ignores the +// Callable. This is useful for executing a function object with a condition +// that corresponds to whether or not the Callable can be safely instantiated. +// It has some overlapping uses with C++17 `if constexpr`. +template <bool Condition> +struct If; + +template <> +struct If</*Condition =*/false> { + template <class Fun, class... P> + static void Invoke(const Fun& /*fun*/, P&&... /*args*/) {} +}; + +template <> +struct If</*Condition =*/true> { + template <class Fun, class... P> + static void Invoke(const Fun& fun, P&&... args) { + // TODO(calabrese) Use std::invoke equivalent instead of function-call. + fun(absl::forward<P>(args)...); + } +}; + +// +// ABSL_INTERNAL_STRINGIZE(...) +// +// This variadic macro transforms its arguments into a c-string literal after +// expansion. +// +// Example: +// +// ABSL_INTERNAL_STRINGIZE(std::array<int, 10>) +// +// Results in: +// +// "std::array<int, 10>" +#define ABSL_INTERNAL_STRINGIZE(...) ABSL_INTERNAL_STRINGIZE_IMPL((__VA_ARGS__)) +#define ABSL_INTERNAL_STRINGIZE_IMPL(arg) ABSL_INTERNAL_STRINGIZE_IMPL2 arg +#define ABSL_INTERNAL_STRINGIZE_IMPL2(...) #__VA_ARGS__ + +} // namespace types_internal +ABSL_NAMESPACE_END +} // namespace absl + +#endif // ABSL_TYPES_INTERNAL_CONFORMANCE_TESTING_HELPERS_H_ |