diff options
Diffstat (limited to 'absl/types/span.h')
-rw-r--r-- | absl/types/span.h | 100 |
1 files changed, 2 insertions, 98 deletions
diff --git a/absl/types/span.h b/absl/types/span.h index e5c4fe1e4dc2..b007fc1fd3df 100644 --- a/absl/types/span.h +++ b/absl/types/span.h @@ -60,114 +60,18 @@ #include <cstddef> #include <initializer_list> #include <iterator> -#include <string> #include <type_traits> #include <utility> -#include "absl/algorithm/algorithm.h" #include "absl/base/internal/throw_delegate.h" #include "absl/base/macros.h" #include "absl/base/optimization.h" -#include "absl/base/port.h" +#include "absl/base/port.h" // TODO(strel): remove this include #include "absl/meta/type_traits.h" +#include "absl/types/internal/span.h" namespace absl { -namespace span_internal { -// A constexpr min function -constexpr size_t Min(size_t a, size_t b) noexcept { return a < b ? a : b; } - -// Wrappers for access to container data pointers. -template <typename C> -constexpr auto GetDataImpl(C& c, char) noexcept // NOLINT(runtime/references) - -> decltype(c.data()) { - return c.data(); -} - -// Before C++17, std::string::data returns a const char* in all cases. -inline char* GetDataImpl(std::string& s, // NOLINT(runtime/references) - int) noexcept { - return &s[0]; -} - -template <typename C> -constexpr auto GetData(C& c) noexcept // NOLINT(runtime/references) - -> decltype(GetDataImpl(c, 0)) { - return GetDataImpl(c, 0); -} - -// Detection idioms for size() and data(). -template <typename C> -using HasSize = - std::is_integral<absl::decay_t<decltype(std::declval<C&>().size())>>; - -// We want to enable conversion from vector<T*> to Span<const T* const> but -// disable conversion from vector<Derived> to Span<Base>. Here we use -// the fact that U** is convertible to Q* const* if and only if Q is the same -// type or a more cv-qualified version of U. We also decay the result type of -// data() to avoid problems with classes which have a member function data() -// which returns a reference. -template <typename T, typename C> -using HasData = - std::is_convertible<absl::decay_t<decltype(GetData(std::declval<C&>()))>*, - T* const*>; - -// Extracts value type from a Container -template <typename C> -struct ElementType { - using type = typename absl::remove_reference_t<C>::value_type; -}; - -template <typename T, size_t N> -struct ElementType<T (&)[N]> { - using type = T; -}; - -template <typename C> -using ElementT = typename ElementType<C>::type; - -template <typename T> -using EnableIfMutable = - typename std::enable_if<!std::is_const<T>::value, int>::type; - -template <template <typename> class SpanT, typename T> -bool EqualImpl(SpanT<T> a, SpanT<T> b) { - static_assert(std::is_const<T>::value, ""); - return absl::equal(a.begin(), a.end(), b.begin(), b.end()); -} - -template <template <typename> class SpanT, typename T> -bool LessThanImpl(SpanT<T> a, SpanT<T> b) { - // We can't use value_type since that is remove_cv_t<T>, so we go the long way - // around. - static_assert(std::is_const<T>::value, ""); - return std::lexicographical_compare(a.begin(), a.end(), b.begin(), b.end()); -} - -// The `IsConvertible` classes here are needed because of the -// `std::is_convertible` bug in libcxx when compiled with GCC. This build -// configuration is used by Android NDK toolchain. Reference link: -// https://bugs.llvm.org/show_bug.cgi?id=27538. -template <typename From, typename To> -struct IsConvertibleHelper { - private: - static std::true_type testval(To); - static std::false_type testval(...); - - public: - using type = decltype(testval(std::declval<From>())); -}; - -template <typename From, typename To> -struct IsConvertible : IsConvertibleHelper<From, To>::type {}; - -// TODO(zhangxy): replace `IsConvertible` with `std::is_convertible` once the -// older version of libcxx is not supported. -template <typename From, typename To> -using EnableIfConvertibleTo = - typename std::enable_if<IsConvertible<From, To>::value>::type; -} // namespace span_internal - //------------------------------------------------------------------------------ // Span //------------------------------------------------------------------------------ |