summaryrefslogtreecommitdiffstats
path: root/mfbt
diff options
context:
space:
mode:
Diffstat (limited to 'mfbt')
-rw-r--r--mfbt/Casting.h13
-rw-r--r--mfbt/Range.h32
-rw-r--r--mfbt/Span.h1041
-rw-r--r--mfbt/moz.build1
-rw-r--r--mfbt/tests/gtest/TestSpan.cpp2079
-rw-r--r--mfbt/tests/gtest/moz.build15
-rw-r--r--mfbt/tests/moz.build5
7 files changed, 3186 insertions, 0 deletions
diff --git a/mfbt/Casting.h b/mfbt/Casting.h
index a7d0fb50d..adf2c9045 100644
--- a/mfbt/Casting.h
+++ b/mfbt/Casting.h
@@ -238,6 +238,19 @@ AssertedCast(const From aFrom)
return static_cast<To>(aFrom);
}
+/**
+ * Cast a value of integral type |From| to a value of integral type |To|,
+ * release asserting that the cast will be a safe cast per C++ (that is, that
+ * |to| is in the range of values permitted for the type |From|).
+ */
+template<typename To, typename From>
+inline To
+ReleaseAssertedCast(const From aFrom)
+{
+ MOZ_RELEASE_ASSERT((detail::IsInBounds<From, To>(aFrom)));
+ return static_cast<To>(aFrom);
+}
+
} // namespace mozilla
#endif /* mozilla_Casting_h */
diff --git a/mfbt/Range.h b/mfbt/Range.h
index 47d91bb0c..753fe07f8 100644
--- a/mfbt/Range.h
+++ b/mfbt/Range.h
@@ -9,6 +9,7 @@
#include "mozilla/RangedPtr.h"
#include "mozilla/TypeTraits.h"
+#include "mozilla/Span.h"
#include <stddef.h>
@@ -44,6 +45,19 @@ public:
mEnd(aOther.mEnd)
{}
+ MOZ_IMPLICIT Range(Span<T> aSpan)
+ : Range(aSpan.Elements(), aSpan.Length())
+ {
+ }
+
+ template<typename U,
+ class = typename EnableIf<IsConvertible<U (*)[], T (*)[]>::value,
+ int>::Type>
+ MOZ_IMPLICIT Range(const Span<U>& aSpan)
+ : Range(aSpan.Elements(), aSpan.Length())
+ {
+ }
+
RangedPtr<T> begin() const { return mStart; }
RangedPtr<T> end() const { return mEnd; }
size_t length() const { return mEnd - mStart; }
@@ -51,8 +65,26 @@ public:
T& operator[](size_t aOffset) const { return mStart[aOffset]; }
explicit operator bool() const { return mStart != nullptr; }
+
+ operator Span<T>() { return Span<T>(mStart.get(), length()); }
+
+ operator Span<const T>() const { return Span<T>(mStart.get(), length()); }
};
+template<class T>
+Span<T>
+MakeSpan(Range<T>& aRange)
+{
+ return aRange;
+}
+
+template<class T>
+Span<const T>
+MakeSpan(const Range<T>& aRange)
+{
+ return aRange;
+}
+
} // namespace mozilla
#endif /* mozilla_Range_h */
diff --git a/mfbt/Span.h b/mfbt/Span.h
new file mode 100644
index 000000000..5acaafcbd
--- /dev/null
+++ b/mfbt/Span.h
@@ -0,0 +1,1041 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
+//
+// This code is licensed under the MIT License (MIT).
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+// Adapted from https://github.com/Microsoft/GSL/blob/3819df6e378ffccf0e29465afe99c3b324c2aa70/include/gsl/span
+// and https://github.com/Microsoft/GSL/blob/3819df6e378ffccf0e29465afe99c3b324c2aa70/include/gsl/gsl_util
+
+#ifndef mozilla_Span_h
+#define mozilla_Span_h
+
+#include "mozilla/Array.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/Casting.h"
+#include "mozilla/IntegerTypeTraits.h"
+#include "mozilla/Move.h"
+#include "mozilla/TypeTraits.h"
+#include "mozilla/UniquePtr.h"
+
+#include <algorithm>
+#include <array>
+#include <cstring>
+#include <iterator>
+
+// Classifications for reasons why constexpr was removed in C++14 to C++11
+// conversion. Once we upgrade compilers, we can try defining each of these
+// to constexpr to restore a category of constexprs at a time.
+#define MOZ_SPAN_ASSERTION_CONSTEXPR
+#define MOZ_SPAN_GCC_CONSTEXPR
+#define MOZ_SPAN_EXPLICITLY_DEFAULTED_CONSTEXPR
+#define MOZ_SPAN_CONSTEXPR_NOT_JUST_RETURN
+#define MOZ_SPAN_NON_CONST_CONSTEXPR
+
+#ifdef _MSC_VER
+#pragma warning(push)
+
+// turn off some warnings that are noisy about our MOZ_RELEASE_ASSERT statements
+#pragma warning(disable : 4127) // conditional expression is constant
+
+// blanket turn off warnings from CppCoreCheck for now
+// so people aren't annoyed by them when running the tool.
+// more targeted suppressions will be added in a future update to the GSL
+#pragma warning(disable : 26481 26482 26483 26485 26490 26491 26492 26493 26495)
+
+#if _MSC_VER < 1910
+#pragma push_macro("constexpr")
+#define constexpr /*constexpr*/
+
+#endif // _MSC_VER < 1910
+#endif // _MSC_VER
+
+namespace mozilla {
+
+// Stuff from gsl_util
+
+// narrow_cast(): a searchable way to do narrowing casts of values
+template<class T, class U>
+inline constexpr T
+narrow_cast(U&& u)
+{
+ return static_cast<T>(mozilla::Forward<U>(u));
+}
+
+// end gsl_util
+
+// [views.constants], constants
+// This was -1 in gsl::span, but using size_t for sizes instead of ptrdiff_t
+// and reserving a magic value that realistically doesn't occur in
+// compile-time-constant Span sizes makes things a lot less messy in terms of
+// comparison between signed and unsigned.
+constexpr const size_t dynamic_extent = mozilla::MaxValue<size_t>::value;
+
+template<class ElementType, size_t Extent = dynamic_extent>
+class Span;
+
+// implementation details
+namespace span_details {
+
+// C++14 types that we don't have because we build as C++11.
+template<class T>
+using remove_cv_t = typename mozilla::RemoveCV<T>::Type;
+template<class T>
+using remove_const_t = typename mozilla::RemoveConst<T>::Type;
+template<bool B, class T, class F>
+using conditional_t = typename mozilla::Conditional<B, T, F>::Type;
+template<class T>
+using add_pointer_t = typename mozilla::AddPointer<T>::Type;
+template<bool B, class T = void>
+using enable_if_t = typename mozilla::EnableIf<B, T>::Type;
+
+template<class T>
+struct is_span_oracle : mozilla::FalseType
+{
+};
+
+template<class ElementType, size_t Extent>
+struct is_span_oracle<mozilla::Span<ElementType, Extent>> : mozilla::TrueType
+{
+};
+
+template<class T>
+struct is_span : public is_span_oracle<remove_cv_t<T>>
+{
+};
+
+template<class T>
+struct is_std_array_oracle : mozilla::FalseType
+{
+};
+
+template<class ElementType, size_t Extent>
+struct is_std_array_oracle<std::array<ElementType, Extent>> : mozilla::TrueType
+{
+};
+
+template<class T>
+struct is_std_array : public is_std_array_oracle<remove_cv_t<T>>
+{
+};
+
+template<size_t From, size_t To>
+struct is_allowed_extent_conversion
+ : public mozilla::IntegralConstant<bool,
+ From == To ||
+ From == mozilla::dynamic_extent ||
+ To == mozilla::dynamic_extent>
+{
+};
+
+template<class From, class To>
+struct is_allowed_element_type_conversion
+ : public mozilla::IntegralConstant<bool, mozilla::IsConvertible<From (*)[], To (*)[]>::value>
+{
+};
+
+template<class Span, bool IsConst>
+class span_iterator
+{
+ using element_type_ = typename Span::element_type;
+
+public:
+ using iterator_category = std::random_access_iterator_tag;
+ using value_type = remove_const_t<element_type_>;
+ using difference_type = typename Span::index_type;
+
+ using reference = conditional_t<IsConst, const element_type_, element_type_>&;
+ using pointer = add_pointer_t<reference>;
+
+ constexpr span_iterator() : span_iterator(nullptr, 0) {}
+
+ MOZ_SPAN_ASSERTION_CONSTEXPR span_iterator(const Span* span,
+ typename Span::index_type index)
+ : span_(span)
+ , index_(index)
+ {
+ MOZ_RELEASE_ASSERT(span == nullptr ||
+ (index_ >= 0 && index <= span_->Length()));
+ }
+
+ friend class span_iterator<Span, true>;
+ constexpr MOZ_IMPLICIT span_iterator(const span_iterator<Span, false>& other)
+ : span_iterator(other.span_, other.index_)
+ {
+ }
+
+ MOZ_SPAN_EXPLICITLY_DEFAULTED_CONSTEXPR span_iterator<Span, IsConst>&
+ operator=(const span_iterator<Span, IsConst>&) = default;
+
+ MOZ_SPAN_GCC_CONSTEXPR reference operator*() const
+ {
+ MOZ_RELEASE_ASSERT(span_);
+ return (*span_)[index_];
+ }
+
+ MOZ_SPAN_GCC_CONSTEXPR pointer operator->() const
+ {
+ MOZ_RELEASE_ASSERT(span_);
+ return &((*span_)[index_]);
+ }
+
+ MOZ_SPAN_NON_CONST_CONSTEXPR span_iterator& operator++()
+ {
+ MOZ_RELEASE_ASSERT(span_ && index_ >= 0 && index_ < span_->Length());
+ ++index_;
+ return *this;
+ }
+
+ MOZ_SPAN_NON_CONST_CONSTEXPR span_iterator operator++(int)
+ {
+ auto ret = *this;
+ ++(*this);
+ return ret;
+ }
+
+ MOZ_SPAN_NON_CONST_CONSTEXPR span_iterator& operator--()
+ {
+ MOZ_RELEASE_ASSERT(span_ && index_ > 0 && index_ <= span_->Length());
+ --index_;
+ return *this;
+ }
+
+ MOZ_SPAN_NON_CONST_CONSTEXPR span_iterator operator--(int)
+ {
+ auto ret = *this;
+ --(*this);
+ return ret;
+ }
+
+ MOZ_SPAN_CONSTEXPR_NOT_JUST_RETURN span_iterator
+ operator+(difference_type n) const
+ {
+ auto ret = *this;
+ return ret += n;
+ }
+
+ MOZ_SPAN_GCC_CONSTEXPR span_iterator& operator+=(difference_type n)
+ {
+ MOZ_RELEASE_ASSERT(span_ && (index_ + n) >= 0 &&
+ (index_ + n) <= span_->Length());
+ index_ += n;
+ return *this;
+ }
+
+ MOZ_SPAN_CONSTEXPR_NOT_JUST_RETURN span_iterator
+ operator-(difference_type n) const
+ {
+ auto ret = *this;
+ return ret -= n;
+ }
+
+ MOZ_SPAN_NON_CONST_CONSTEXPR span_iterator& operator-=(difference_type n)
+
+ {
+ return *this += -n;
+ }
+
+ MOZ_SPAN_GCC_CONSTEXPR difference_type
+ operator-(const span_iterator& rhs) const
+ {
+ MOZ_RELEASE_ASSERT(span_ == rhs.span_);
+ return index_ - rhs.index_;
+ }
+
+ constexpr reference operator[](difference_type n) const
+ {
+ return *(*this + n);
+ }
+
+ constexpr friend bool operator==(const span_iterator& lhs,
+ const span_iterator& rhs)
+ {
+ return lhs.span_ == rhs.span_ && lhs.index_ == rhs.index_;
+ }
+
+ constexpr friend bool operator!=(const span_iterator& lhs,
+ const span_iterator& rhs)
+ {
+ return !(lhs == rhs);
+ }
+
+ MOZ_SPAN_GCC_CONSTEXPR friend bool operator<(const span_iterator& lhs,
+ const span_iterator& rhs)
+ {
+ MOZ_RELEASE_ASSERT(lhs.span_ == rhs.span_);
+ return lhs.index_ < rhs.index_;
+ }
+
+ constexpr friend bool operator<=(const span_iterator& lhs,
+ const span_iterator& rhs)
+ {
+ return !(rhs < lhs);
+ }
+
+ constexpr friend bool operator>(const span_iterator& lhs,
+ const span_iterator& rhs)
+ {
+ return rhs < lhs;
+ }
+
+ constexpr friend bool operator>=(const span_iterator& lhs,
+ const span_iterator& rhs)
+ {
+ return !(rhs > lhs);
+ }
+
+ void swap(span_iterator& rhs)
+ {
+ std::swap(index_, rhs.index_);
+ std::swap(span_, rhs.span_);
+ }
+
+protected:
+ const Span* span_;
+ size_t index_;
+};
+
+template<class Span, bool IsConst>
+inline constexpr span_iterator<Span, IsConst>
+operator+(typename span_iterator<Span, IsConst>::difference_type n,
+ const span_iterator<Span, IsConst>& rhs)
+{
+ return rhs + n;
+}
+
+template<size_t Ext>
+class extent_type
+{
+public:
+ using index_type = size_t;
+
+ static_assert(Ext >= 0, "A fixed-size Span must be >= 0 in size.");
+
+ constexpr extent_type() {}
+
+ template<index_type Other>
+ MOZ_SPAN_ASSERTION_CONSTEXPR MOZ_IMPLICIT extent_type(extent_type<Other> ext)
+ {
+ static_assert(
+ Other == Ext || Other == dynamic_extent,
+ "Mismatch between fixed-size extent and size of initializing data.");
+ MOZ_RELEASE_ASSERT(ext.size() == Ext);
+ }
+
+ MOZ_SPAN_ASSERTION_CONSTEXPR MOZ_IMPLICIT extent_type(index_type length)
+ {
+ MOZ_RELEASE_ASSERT(length == Ext);
+ }
+
+ constexpr index_type size() const { return Ext; }
+};
+
+template<>
+class extent_type<dynamic_extent>
+{
+public:
+ using index_type = size_t;
+
+ template<index_type Other>
+ explicit constexpr extent_type(extent_type<Other> ext)
+ : size_(ext.size())
+ {
+ }
+
+ explicit constexpr extent_type(index_type length)
+ : size_(length)
+ {
+ }
+
+ constexpr index_type size() const { return size_; }
+
+private:
+ index_type size_;
+};
+} // namespace span_details
+
+/**
+ * Span - slices for C++
+ *
+ * Span implements Rust's slice concept for C++. It's called "Span" instead of
+ * "Slice" to follow the naming used in C++ Core Guidelines.
+ *
+ * A Span wraps a pointer and a length that identify a non-owning view to a
+ * contiguous block of memory of objects of the same type. Various types,
+ * including (pre-decay) C arrays, XPCOM strings, nsTArray, mozilla::Array,
+ * mozilla::Range and contiguous standard-library containers, auto-convert
+ * into Spans when attempting to pass them as arguments to methods that take
+ * Spans. MakeSpan() functions can be used for explicit conversion in other
+ * contexts. (Span itself autoconverts into mozilla::Range.)
+ *
+ * Like Rust's slices, Span provides safety against out-of-bounds access by
+ * performing run-time bound checks. However, unlike Rust's slices, Span
+ * cannot provide safety against use-after-free.
+ *
+ * (Note: Span is like Rust's slice only conceptually. Due to the lack of
+ * ABI guarantees, you should still decompose spans/slices to raw pointer
+ * and length parts when crossing the FFI.)
+ *
+ * In addition to having constructors and MakeSpan() functions that take
+ * various well-known types, a Span for an arbitrary type can be constructed
+ * (via constructor or MakeSpan()) from a pointer and a length or a pointer
+ * and another pointer pointing just past the last element.
+ *
+ * A Span<const char> can be obtained for const char* pointing to a
+ * zero-terminated C string using the MakeCStringSpan() function. A
+ * corresponding implicit constructor does not exist in order to avoid
+ * accidental construction in cases where const char* does not point to a
+ * zero-terminated C string.
+ *
+ * Span has methods that follow the Mozilla naming style and methods that
+ * don't. The methods that follow the Mozilla naming style are meant to be
+ * used directly from Mozilla code. The methods that don't are meant for
+ * integration with C++11 range-based loops and with meta-programming that
+ * expects the same methods that are found on the standard-library
+ * containers. For example, to decompose a Span into its parts in Mozilla
+ * code, use Elements() and Length() (as with nsTArray) instead of data()
+ * and size() (as with std::vector).
+ *
+ * The pointer and length wrapped by a Span cannot be changed after a Span has
+ * been created. When new values are required, simply create a new Span. Span
+ * has a method called Subspan() that works analogously to the Substring()
+ * method of XPCOM strings taking a start index and an optional length. As a
+ * Mozilla extension (relative to Microsoft's gsl::span that mozilla::Span is
+ * based on), Span has methods From(start), To(end) and FromTo(start, end)
+ * that correspond to Rust's &slice[start..], &slice[..end] and
+ * &slice[start..end], respectively. (That is, the end index is the index of
+ * the first element not to be included in the new subspan.)
+ *
+ * When indicating a Span that's only read from, const goes inside the type
+ * parameter. Don't put const in front of Span. That is:
+ * size_t ReadsFromOneSpanAndWritesToAnother(Span<const uint8_t> aReadFrom,
+ * Span<uint8_t> aWrittenTo);
+ *
+ * Any Span<const T> can be viewed as Span<const uint8_t> using the function
+ * AsBytes(). Any Span<T> can be viewed as Span<uint8_t> using the function
+ * AsWritableBytes().
+ */
+template<class ElementType, size_t Extent>
+class Span
+{
+public:
+ // constants and types
+ using element_type = ElementType;
+ using index_type = size_t;
+ using pointer = element_type*;
+ using reference = element_type&;
+
+ using iterator =
+ span_details::span_iterator<Span<ElementType, Extent>, false>;
+ using const_iterator =
+ span_details::span_iterator<Span<ElementType, Extent>, true>;
+ using reverse_iterator = std::reverse_iterator<iterator>;
+ using const_reverse_iterator = std::reverse_iterator<const_iterator>;
+
+ constexpr static const index_type extent = Extent;
+
+ // [Span.cons], Span constructors, copy, assignment, and destructor
+ // "Dependent" is needed to make "span_details::enable_if_t<(Dependent || Extent == 0 || Extent == mozilla::MaxValue<size_t>::value)>" SFINAE,
+ // since "span_details::enable_if_t<(Extent == 0 || Extent == mozilla::MaxValue<size_t>::value)>" is ill-formed when Extent is neither of the extreme values.
+ /**
+ * Constructor with no args.
+ */
+ template<
+ bool Dependent = false,
+ class = span_details::enable_if_t<
+ (Dependent || Extent == 0 || Extent == mozilla::MaxValue<size_t>::value)>>
+ constexpr Span()
+ : storage_(nullptr, span_details::extent_type<0>())
+ {
+ }
+
+ /**
+ * Constructor for nullptr.
+ */
+ constexpr MOZ_IMPLICIT Span(std::nullptr_t) : Span() {}
+
+ /**
+ * Constructor for pointer and length.
+ */
+ constexpr Span(pointer aPtr, index_type aLength)
+ : storage_(aPtr, aLength)
+ {
+ }
+
+ /**
+ * Constructor for start pointer and pointer past end.
+ */
+ constexpr Span(pointer aStartPtr, pointer aEndPtr)
+ : storage_(aStartPtr, std::distance(aStartPtr, aEndPtr))
+ {
+ }
+
+ /**
+ * Constructor for C array.
+ */
+ template<size_t N>
+ constexpr MOZ_IMPLICIT Span(element_type (&aArr)[N])
+ : storage_(&aArr[0], span_details::extent_type<N>())
+ {
+ }
+
+ /**
+ * Constructor for std::array.
+ */
+ template<size_t N,
+ class ArrayElementType = span_details::remove_const_t<element_type>>
+ constexpr MOZ_IMPLICIT Span(std::array<ArrayElementType, N>& aArr)
+ : storage_(&aArr[0], span_details::extent_type<N>())
+ {
+ }
+
+ /**
+ * Constructor for const std::array.
+ */
+ template<size_t N>
+ constexpr MOZ_IMPLICIT Span(
+ const std::array<span_details::remove_const_t<element_type>, N>& aArr)
+ : storage_(&aArr[0], span_details::extent_type<N>())
+ {
+ }
+
+ /**
+ * Constructor for mozilla::Array.
+ */
+ template<size_t N,
+ class ArrayElementType = span_details::remove_const_t<element_type>>
+ constexpr MOZ_IMPLICIT Span(mozilla::Array<ArrayElementType, N>& aArr)
+ : storage_(&aArr[0], span_details::extent_type<N>())
+ {
+ }
+
+ /**
+ * Constructor for const mozilla::Array.
+ */
+ template<size_t N>
+ constexpr MOZ_IMPLICIT Span(
+ const mozilla::Array<span_details::remove_const_t<element_type>, N>& aArr)
+ : storage_(&aArr[0], span_details::extent_type<N>())
+ {
+ }
+
+ /**
+ * Constructor for mozilla::UniquePtr holding an array and length.
+ */
+ template<class ArrayElementType = std::add_pointer<element_type>>
+ constexpr Span(const mozilla::UniquePtr<ArrayElementType>& aPtr,
+ index_type aLength)
+ : storage_(aPtr.get(), aLength)
+ {
+ }
+
+ // NB: the SFINAE here uses .data() as a incomplete/imperfect proxy for the requirement
+ // on Container to be a contiguous sequence container.
+ /**
+ * Constructor for standard-library containers.
+ */
+ template<
+ class Container,
+ class = span_details::enable_if_t<
+ !span_details::is_span<Container>::value &&
+ !span_details::is_std_array<Container>::value &&
+ mozilla::IsConvertible<typename Container::pointer, pointer>::value &&
+ mozilla::IsConvertible<typename Container::pointer,
+ decltype(mozilla::DeclVal<Container>().data())>::value>>
+ constexpr MOZ_IMPLICIT Span(Container& cont)
+ : Span(cont.data(), ReleaseAssertedCast<index_type>(cont.size()))
+ {
+ }
+
+ /**
+ * Constructor for standard-library containers (const version).
+ */
+ template<
+ class Container,
+ class = span_details::enable_if_t<
+ mozilla::IsConst<element_type>::value &&
+ !span_details::is_span<Container>::value &&
+ mozilla::IsConvertible<typename Container::pointer, pointer>::value &&
+ mozilla::IsConvertible<typename Container::pointer,
+ decltype(mozilla::DeclVal<Container>().data())>::value>>
+ constexpr MOZ_IMPLICIT Span(const Container& cont)
+ : Span(cont.data(), ReleaseAssertedCast<index_type>(cont.size()))
+ {
+ }
+
+ /**
+ * Constructor from other Span.
+ */
+ constexpr Span(const Span& other) = default;
+
+ /**
+ * Constructor from other Span.
+ */
+ constexpr Span(Span&& other) = default;
+
+ /**
+ * Constructor from other Span with conversion of element type.
+ */
+ template<
+ class OtherElementType,
+ size_t OtherExtent,
+ class = span_details::enable_if_t<
+ span_details::is_allowed_extent_conversion<OtherExtent, Extent>::value &&
+ span_details::is_allowed_element_type_conversion<OtherElementType,
+ element_type>::value>>
+ constexpr MOZ_IMPLICIT Span(const Span<OtherElementType, OtherExtent>& other)
+ : storage_(other.data(),
+ span_details::extent_type<OtherExtent>(other.size()))
+ {
+ }
+
+ /**
+ * Constructor from other Span with conversion of element type.
+ */
+ template<
+ class OtherElementType,
+ size_t OtherExtent,
+ class = span_details::enable_if_t<
+ span_details::is_allowed_extent_conversion<OtherExtent, Extent>::value &&
+ span_details::is_allowed_element_type_conversion<OtherElementType,
+ element_type>::value>>
+ constexpr MOZ_IMPLICIT Span(Span<OtherElementType, OtherExtent>&& other)
+ : storage_(other.data(),
+ span_details::extent_type<OtherExtent>(other.size()))
+ {
+ }
+
+ ~Span() = default;
+ MOZ_SPAN_EXPLICITLY_DEFAULTED_CONSTEXPR Span& operator=(const Span& other)
+ = default;
+
+ MOZ_SPAN_EXPLICITLY_DEFAULTED_CONSTEXPR Span& operator=(Span&& other)
+ = default;
+
+ // [Span.sub], Span subviews
+ /**
+ * Subspan with first N elements with compile-time N.
+ */
+ template<size_t Count>
+ MOZ_SPAN_GCC_CONSTEXPR Span<element_type, Count> First() const
+ {
+ MOZ_RELEASE_ASSERT(Count <= size());
+ return { data(), Count };
+ }
+
+ /**
+ * Subspan with last N elements with compile-time N.
+ */
+ template<size_t Count>
+ MOZ_SPAN_GCC_CONSTEXPR Span<element_type, Count> Last() const
+ {
+ MOZ_RELEASE_ASSERT(Count <= size());
+ return { data() + (size() - Count), Count };
+ }
+
+ /**
+ * Subspan with compile-time start index and length.
+ */
+ template<size_t Offset, size_t Count = dynamic_extent>
+ MOZ_SPAN_GCC_CONSTEXPR Span<element_type, Count> Subspan() const
+ {
+ MOZ_RELEASE_ASSERT(Offset <= size() &&
+ (Count == dynamic_extent || (Offset + Count <= size())));
+ return { data() + Offset,
+ Count == dynamic_extent ? size() - Offset : Count };
+ }
+
+ /**
+ * Subspan with first N elements with run-time N.
+ */
+ MOZ_SPAN_GCC_CONSTEXPR Span<element_type, dynamic_extent> First(
+ index_type aCount) const
+ {
+ MOZ_RELEASE_ASSERT(aCount <= size());
+ return { data(), aCount };
+ }
+
+ /**
+ * Subspan with last N elements with run-time N.
+ */
+ MOZ_SPAN_GCC_CONSTEXPR Span<element_type, dynamic_extent> Last(
+ index_type aCount) const
+ {
+ MOZ_RELEASE_ASSERT(aCount <= size());
+ return { data() + (size() - aCount), aCount };
+ }
+
+ /**
+ * Subspan with run-time start index and length.
+ */
+ MOZ_SPAN_GCC_CONSTEXPR Span<element_type, dynamic_extent> Subspan(
+ index_type aStart,
+ index_type aLength = dynamic_extent) const
+ {
+ MOZ_RELEASE_ASSERT(aStart <= size() &&
+ (aLength == dynamic_extent ||
+ (aStart + aLength <= size())));
+ return { data() + aStart,
+ aLength == dynamic_extent ? size() - aStart : aLength };
+ }
+
+ /**
+ * Subspan with run-time start index. (Rust's &foo[start..])
+ */
+ MOZ_SPAN_GCC_CONSTEXPR Span<element_type, dynamic_extent> From(
+ index_type aStart) const
+ {
+ return Subspan(aStart);
+ }
+
+ /**
+ * Subspan with run-time exclusive end index. (Rust's &foo[..end])
+ */
+ MOZ_SPAN_GCC_CONSTEXPR Span<element_type, dynamic_extent> To(
+ index_type aEnd) const
+ {
+ return Subspan(0, aEnd);
+ }
+
+ /**
+ * Subspan with run-time start index and exclusive end index.
+ * (Rust's &foo[start..end])
+ */
+ MOZ_SPAN_GCC_CONSTEXPR Span<element_type, dynamic_extent> FromTo(
+ index_type aStart,
+ index_type aEnd) const
+ {
+ MOZ_RELEASE_ASSERT(aStart <= aEnd);
+ return Subspan(aStart, aEnd - aStart);
+ }
+
+ // [Span.obs], Span observers
+ /**
+ * Number of elements in the span.
+ */
+ constexpr index_type Length() const { return size(); }
+
+ /**
+ * Number of elements in the span (standard-libray duck typing version).
+ */
+ constexpr index_type size() const { return storage_.size(); }
+
+ /**
+ * Size of the span in bytes.
+ */
+ constexpr index_type LengthBytes() const { return size_bytes(); }
+
+ /**
+ * Size of the span in bytes (standard-library naming style version).
+ */
+ constexpr index_type size_bytes() const
+ {
+ return size() * narrow_cast<index_type>(sizeof(element_type));
+ }
+
+ /**
+ * Checks if the the length of the span is zero.
+ */
+ constexpr bool IsEmpty() const { return empty(); }
+
+ /**
+ * Checks if the the length of the span is zero (standard-libray duck
+ * typing version).
+ */
+ constexpr bool empty() const { return size() == 0; }
+
+ // [Span.elem], Span element access
+ MOZ_SPAN_GCC_CONSTEXPR reference operator[](index_type idx) const
+ {
+ MOZ_RELEASE_ASSERT(idx < storage_.size());
+ return data()[idx];
+ }
+
+ /**
+ * Access element of span by index (standard-library duck typing version).
+ */
+ constexpr reference at(index_type idx) const { return this->operator[](idx); }
+
+ constexpr reference operator()(index_type idx) const
+ {
+ return this->operator[](idx);
+ }
+
+ /**
+ * Pointer to the first element of the span.
+ */
+ constexpr pointer Elements() const { return data(); }
+
+ /**
+ * Pointer to the first element of the span (standard-libray duck typing version).
+ */
+ constexpr pointer data() const { return storage_.data(); }
+
+ // [Span.iter], Span iterator support
+ iterator begin() const { return { this, 0 }; }
+ iterator end() const { return { this, Length() }; }
+
+ const_iterator cbegin() const { return { this, 0 }; }
+ const_iterator cend() const { return { this, Length() }; }
+
+ reverse_iterator rbegin() const
+ {
+ return reverse_iterator{ end() };
+ }
+ reverse_iterator rend() const
+ {
+ return reverse_iterator{ begin() };
+ }
+
+ const_reverse_iterator crbegin() const
+ {
+ return const_reverse_iterator{ cend() };
+ }
+ const_reverse_iterator crend() const
+ {
+ return const_reverse_iterator{ cbegin() };
+ }
+
+private:
+ // this implementation detail class lets us take advantage of the
+ // empty base class optimization to pay for only storage of a single
+ // pointer in the case of fixed-size Spans
+ template<class ExtentType>
+ class storage_type : public ExtentType
+ {
+ public:
+ template<class OtherExtentType>
+ MOZ_SPAN_ASSERTION_CONSTEXPR storage_type(pointer elements,
+ OtherExtentType ext)
+ : ExtentType(ext)
+ , data_(elements)
+ {
+ MOZ_RELEASE_ASSERT(
+ (!elements && ExtentType::size() == 0) ||
+ (elements && ExtentType::size() != mozilla::MaxValue<size_t>::value));
+ }
+
+ constexpr pointer data() const { return data_; }
+
+ private:
+ pointer data_;
+ };
+
+ storage_type<span_details::extent_type<Extent>> storage_;
+};
+
+// [Span.comparison], Span comparison operators
+template<class ElementType, size_t FirstExtent, size_t SecondExtent>
+inline constexpr bool
+operator==(const Span<ElementType, FirstExtent>& l,
+ const Span<ElementType, SecondExtent>& r)
+{
+ return (l.size() == r.size()) && std::equal(l.begin(), l.end(), r.begin());
+}
+
+template<class ElementType, size_t Extent>
+inline constexpr bool
+operator!=(const Span<ElementType, Extent>& l,
+ const Span<ElementType, Extent>& r)
+{
+ return !(l == r);
+}
+
+template<class ElementType, size_t Extent>
+inline constexpr bool
+operator<(const Span<ElementType, Extent>& l,
+ const Span<ElementType, Extent>& r)
+{
+ return std::lexicographical_compare(l.begin(), l.end(), r.begin(), r.end());
+}
+
+template<class ElementType, size_t Extent>
+inline constexpr bool
+operator<=(const Span<ElementType, Extent>& l,
+ const Span<ElementType, Extent>& r)
+{
+ return !(l > r);
+}
+
+template<class ElementType, size_t Extent>
+inline constexpr bool
+operator>(const Span<ElementType, Extent>& l,
+ const Span<ElementType, Extent>& r)
+{
+ return r < l;
+}
+
+template<class ElementType, size_t Extent>
+inline constexpr bool
+operator>=(const Span<ElementType, Extent>& l,
+ const Span<ElementType, Extent>& r)
+{
+ return !(l < r);
+}
+
+namespace span_details {
+// if we only supported compilers with good constexpr support then
+// this pair of classes could collapse down to a constexpr function
+
+// we should use a narrow_cast<> to go to size_t, but older compilers may not see it as
+// constexpr
+// and so will fail compilation of the template
+template<class ElementType, size_t Extent>
+struct calculate_byte_size
+ : mozilla::IntegralConstant<size_t,
+ static_cast<size_t>(sizeof(ElementType) *
+ static_cast<size_t>(Extent))>
+{
+};
+
+template<class ElementType>
+struct calculate_byte_size<ElementType, dynamic_extent>
+ : mozilla::IntegralConstant<size_t, dynamic_extent>
+{
+};
+}
+
+// [Span.objectrep], views of object representation
+/**
+ * View span as Span<const uint8_t>.
+ */
+template<class ElementType, size_t Extent>
+Span<const uint8_t,
+ span_details::calculate_byte_size<ElementType, Extent>::value>
+AsBytes(Span<ElementType, Extent> s)
+{
+ return { reinterpret_cast<const uint8_t*>(s.data()), s.size_bytes() };
+}
+
+/**
+ * View span as Span<uint8_t>.
+ */
+template<class ElementType,
+ size_t Extent,
+ class = span_details::enable_if_t<!mozilla::IsConst<ElementType>::value>>
+Span<uint8_t, span_details::calculate_byte_size<ElementType, Extent>::value>
+AsWritableBytes(Span<ElementType, Extent> s)
+{
+ return { reinterpret_cast<uint8_t*>(s.data()), s.size_bytes() };
+}
+
+//
+// MakeSpan() - Utility functions for creating Spans
+//
+/**
+ * Create span from pointer and length.
+ */
+template<class ElementType>
+Span<ElementType>
+MakeSpan(ElementType* aPtr, typename Span<ElementType>::index_type aLength)
+{
+ return Span<ElementType>(aPtr, aLength);
+}
+
+/**
+ * Create span from start pointer and pointer past end.
+ */
+template<class ElementType>
+Span<ElementType>
+MakeSpan(ElementType* aStartPtr, ElementType* aEndPtr)
+{
+ return Span<ElementType>(aStartPtr, aEndPtr);
+}
+
+/**
+ * Create span from C array.
+ */
+template<class ElementType, size_t N>
+Span<ElementType> MakeSpan(ElementType (&aArr)[N])
+{
+ return Span<ElementType>(aArr);
+}
+
+/**
+ * Create span from mozilla::Array.
+ */
+template<class ElementType, size_t N>
+Span<ElementType>
+MakeSpan(mozilla::Array<ElementType, N>& aArr)
+{
+ return aArr;
+}
+
+/**
+ * Create span from const mozilla::Array.
+ */
+template<class ElementType, size_t N>
+Span<const ElementType>
+MakeSpan(const mozilla::Array<ElementType, N>& arr)
+{
+ return arr;
+}
+
+/**
+ * Create span from standard-library container.
+ */
+template<class Container>
+Span<typename Container::value_type>
+MakeSpan(Container& cont)
+{
+ return Span<typename Container::value_type>(cont);
+}
+
+/**
+ * Create span from standard-library container (const version).
+ */
+template<class Container>
+Span<const typename Container::value_type>
+MakeSpan(const Container& cont)
+{
+ return Span<const typename Container::value_type>(cont);
+}
+
+/**
+ * Create span from smart pointer and length.
+ */
+template<class Ptr>
+Span<typename Ptr::element_type>
+MakeSpan(Ptr& aPtr, size_t aLength)
+{
+ return Span<typename Ptr::element_type>(aPtr, aLength);
+}
+
+/**
+ * Create span from C string.
+ */
+inline Span<const char>
+MakeCStringSpan(const char* aStr)
+{
+ return Span<const char>(aStr, std::strlen(aStr));
+}
+
+} // namespace mozilla
+
+#ifdef _MSC_VER
+#if _MSC_VER < 1910
+#undef constexpr
+#pragma pop_macro("constexpr")
+
+#endif // _MSC_VER < 1910
+
+#pragma warning(pop)
+#endif // _MSC_VER
+
+#undef MOZ_SPAN_ASSERTION_CONSTEXPR
+#undef MOZ_SPAN_GCC_CONSTEXPR
+#undef MOZ_SPAN_EXPLICITLY_DEFAULTED_CONSTEXPR
+#undef MOZ_SPAN_CONSTEXPR_NOT_JUST_RETURN
+#undef MOZ_SPAN_NON_CONST_CONSTEXPR
+
+#endif // mozilla_Span_h
diff --git a/mfbt/moz.build b/mfbt/moz.build
index 897a686f4..ea3c3b701 100644
--- a/mfbt/moz.build
+++ b/mfbt/moz.build
@@ -82,6 +82,7 @@ EXPORTS.mozilla = [
'SegmentedVector.h',
'SHA1.h',
'SizePrintfMacros.h',
+ 'Span.h',
'SplayTree.h',
'Sprintf.h',
'StaticAnalysisFunctions.h',
diff --git a/mfbt/tests/gtest/TestSpan.cpp b/mfbt/tests/gtest/TestSpan.cpp
new file mode 100644
index 000000000..f3aa000a4
--- /dev/null
+++ b/mfbt/tests/gtest/TestSpan.cpp
@@ -0,0 +1,2079 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+// Copyright (c) 2015 Microsoft Corporation. All rights reserved.
+//
+// This code is licensed under the MIT License (MIT).
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+// Adapted from https://github.com/Microsoft/GSL/blob/3819df6e378ffccf0e29465afe99c3b324c2aa70/tests/Span_tests.cpp
+
+#include "gtest/gtest.h"
+
+#include "mozilla/Span.h"
+
+#include "nsString.h"
+#include "nsTArray.h"
+#include "mozilla/Range.h"
+#include "mozilla/TypeTraits.h"
+
+#define SPAN_TEST(name) TEST(SpanTest, name)
+#define CHECK_THROW(a, b)
+
+using namespace std;
+using namespace mozilla;
+
+static_assert(IsConvertible<Range<int>, Span<const int>>::value,
+ "Range should convert into const");
+static_assert(IsConvertible<Range<const int>, Span<const int>>::value,
+ "const Range should convert into const");
+static_assert(!IsConvertible<Range<const int>, Span<int>>::value,
+ "Range should not drop const in conversion");
+static_assert(IsConvertible<Span<int>, Range<const int>>::value,
+ "Span should convert into const");
+static_assert(IsConvertible<Span<const int>, Range<const int>>::value,
+ "const Span should convert into const");
+static_assert(!IsConvertible<Span<const int>, Range<int>>::value,
+ "Span should not drop const in conversion");
+static_assert(IsConvertible<Span<const int>, Span<const int>>::value,
+ "const Span should convert into const");
+static_assert(IsConvertible<Span<int>, Span<const int>>::value,
+ "Span should convert into const");
+static_assert(!IsConvertible<Span<const int>, Span<int>>::value,
+ "Span should not drop const in conversion");
+static_assert(IsConvertible<const nsTArray<int>, Span<const int>>::value,
+ "const nsTArray should convert into const");
+static_assert(IsConvertible<nsTArray<int>, Span<const int>>::value,
+ "nsTArray should convert into const");
+static_assert(!IsConvertible<const nsTArray<int>, Span<int>>::value,
+ "nsTArray should not drop const in conversion");
+static_assert(IsConvertible<nsTArray<const int>, Span<const int>>::value,
+ "nsTArray should convert into const");
+static_assert(!IsConvertible<nsTArray<const int>, Span<int>>::value,
+ "nsTArray should not drop const in conversion");
+
+namespace {
+struct BaseClass
+{
+};
+struct DerivedClass : BaseClass
+{
+};
+}
+
+void
+AssertSpanOfThreeInts(Span<const int> s)
+{
+ ASSERT_EQ(s.size(), 3U);
+ ASSERT_EQ(s[0], 1);
+ ASSERT_EQ(s[1], 2);
+ ASSERT_EQ(s[2], 3);
+}
+
+void
+AssertSpanOfThreeChars(Span<const char> s)
+{
+ ASSERT_EQ(s.size(), 3U);
+ ASSERT_EQ(s[0], 'a');
+ ASSERT_EQ(s[1], 'b');
+ ASSERT_EQ(s[2], 'c');
+}
+
+void
+AssertSpanOfThreeChar16s(Span<const char16_t> s)
+{
+ ASSERT_EQ(s.size(), 3U);
+ ASSERT_EQ(s[0], 'a');
+ ASSERT_EQ(s[1], 'b');
+ ASSERT_EQ(s[2], 'c');
+}
+
+void
+AssertSpanOfThreeCharsViaString(const nsACString& aStr)
+{
+ AssertSpanOfThreeChars(aStr);
+}
+
+void
+AssertSpanOfThreeChar16sViaString(const nsAString& aStr)
+{
+ AssertSpanOfThreeChar16s(aStr);
+}
+
+SPAN_TEST(default_constructor)
+{
+ {
+ Span<int> s;
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+
+ Span<const int> cs;
+ ASSERT_EQ(cs.Length(), 0U);
+ ASSERT_EQ(cs.data(), nullptr);
+ }
+
+ {
+ Span<int, 0> s;
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+
+ Span<const int, 0> cs;
+ ASSERT_EQ(cs.Length(), 0U);
+ ASSERT_EQ(cs.data(), nullptr);
+ }
+
+ {
+#ifdef CONFIRM_COMPILATION_ERRORS
+ Span<int, 1> s;
+ ASSERT_EQ(s.Length(), 1U);
+ ASSERT_EQ(s.data(), nullptr); // explains why it can't compile
+#endif
+ }
+
+ {
+ Span<int> s{};
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+
+ Span<const int> cs{};
+ ASSERT_EQ(cs.Length(), 0U);
+ ASSERT_EQ(cs.data(), nullptr);
+ }
+}
+
+SPAN_TEST(size_optimization)
+{
+ {
+ Span<int> s;
+ ASSERT_EQ(sizeof(s), sizeof(int*) + sizeof(size_t));
+ }
+
+ {
+ Span<int, 0> s;
+ ASSERT_EQ(sizeof(s), sizeof(int*));
+ }
+}
+
+SPAN_TEST(from_nullptr_constructor)
+{
+ {
+ Span<int> s = nullptr;
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+
+ Span<const int> cs = nullptr;
+ ASSERT_EQ(cs.Length(), 0U);
+ ASSERT_EQ(cs.data(), nullptr);
+ }
+
+ {
+ Span<int, 0> s = nullptr;
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+
+ Span<const int, 0> cs = nullptr;
+ ASSERT_EQ(cs.Length(), 0U);
+ ASSERT_EQ(cs.data(), nullptr);
+ }
+
+ {
+#ifdef CONFIRM_COMPILATION_ERRORS
+ Span<int, 1> s = nullptr;
+ ASSERT_EQ(s.Length(), 1U);
+ ASSERT_EQ(s.data(), nullptr); // explains why it can't compile
+#endif
+ }
+
+ {
+ Span<int> s{ nullptr };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+
+ Span<const int> cs{ nullptr };
+ ASSERT_EQ(cs.Length(), 0U);
+ ASSERT_EQ(cs.data(), nullptr);
+ }
+
+ {
+ Span<int*> s{ nullptr };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+
+ Span<const int*> cs{ nullptr };
+ ASSERT_EQ(cs.Length(), 0U);
+ ASSERT_EQ(cs.data(), nullptr);
+ }
+}
+
+SPAN_TEST(from_nullptr_length_constructor)
+{
+ {
+ Span<int> s{ nullptr, static_cast<Span<int>::index_type>(0) };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+
+ Span<const int> cs{ nullptr, static_cast<Span<int>::index_type>(0) };
+ ASSERT_EQ(cs.Length(), 0U);
+ ASSERT_EQ(cs.data(), nullptr);
+ }
+
+ {
+ Span<int, 0> s{ nullptr, static_cast<Span<int>::index_type>(0) };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+
+ Span<const int, 0> cs{ nullptr, static_cast<Span<int>::index_type>(0) };
+ ASSERT_EQ(cs.Length(), 0U);
+ ASSERT_EQ(cs.data(), nullptr);
+ }
+
+#if 0
+ {
+ auto workaround_macro = []() { Span<int, 1> s{ nullptr, static_cast<Span<int>::index_type>(0) }; };
+ CHECK_THROW(workaround_macro(), fail_fast);
+ }
+
+ {
+ auto workaround_macro = []() { Span<int> s{nullptr, 1}; };
+ CHECK_THROW(workaround_macro(), fail_fast);
+
+ auto const_workaround_macro = []() { Span<const int> cs{nullptr, 1}; };
+ CHECK_THROW(const_workaround_macro(), fail_fast);
+ }
+
+ {
+ auto workaround_macro = []() { Span<int, 0> s{nullptr, 1}; };
+ CHECK_THROW(workaround_macro(), fail_fast);
+
+ auto const_workaround_macro = []() { Span<const int, 0> s{nullptr, 1}; };
+ CHECK_THROW(const_workaround_macro(), fail_fast);
+ }
+#endif
+ {
+ Span<int*> s{ nullptr, static_cast<Span<int>::index_type>(0) };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+
+ Span<const int*> cs{ nullptr, static_cast<Span<int>::index_type>(0) };
+ ASSERT_EQ(cs.Length(), 0U);
+ ASSERT_EQ(cs.data(), nullptr);
+ }
+}
+
+SPAN_TEST(from_pointer_length_constructor)
+{
+ int arr[4] = { 1, 2, 3, 4 };
+
+ {
+ Span<int> s{ &arr[0], 2 };
+ ASSERT_EQ(s.Length(), 2U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ ASSERT_EQ(s[0], 1);
+ ASSERT_EQ(s[1], 2);
+ }
+
+ {
+ Span<int, 2> s{ &arr[0], 2 };
+ ASSERT_EQ(s.Length(), 2U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ ASSERT_EQ(s[0], 1);
+ ASSERT_EQ(s[1], 2);
+ }
+
+ {
+ int* p = nullptr;
+ Span<int> s{ p, static_cast<Span<int>::index_type>(0) };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+ }
+
+#if 0
+ {
+ int* p = nullptr;
+ auto workaround_macro = [=]() { Span<int> s{p, 2}; };
+ CHECK_THROW(workaround_macro(), fail_fast);
+ }
+#endif
+
+ {
+ auto s = MakeSpan(&arr[0], 2);
+ ASSERT_EQ(s.Length(), 2U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ ASSERT_EQ(s[0], 1);
+ ASSERT_EQ(s[1], 2);
+ }
+
+ {
+ int* p = nullptr;
+ auto s = MakeSpan(p, static_cast<Span<int>::index_type>(0));
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+ }
+
+#if 0
+ {
+ int* p = nullptr;
+ auto workaround_macro = [=]() { MakeSpan(p, 2); };
+ CHECK_THROW(workaround_macro(), fail_fast);
+ }
+#endif
+}
+
+SPAN_TEST(from_pointer_pointer_constructor)
+{
+ int arr[4] = { 1, 2, 3, 4 };
+
+ {
+ Span<int> s{ &arr[0], &arr[2] };
+ ASSERT_EQ(s.Length(), 2U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ ASSERT_EQ(s[0], 1);
+ ASSERT_EQ(s[1], 2);
+ }
+
+ {
+ Span<int, 2> s{ &arr[0], &arr[2] };
+ ASSERT_EQ(s.Length(), 2U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ ASSERT_EQ(s[0], 1);
+ ASSERT_EQ(s[1], 2);
+ }
+
+ {
+ Span<int> s{ &arr[0], &arr[0] };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ Span<int, 0> s{ &arr[0], &arr[0] };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ // this will fail the std::distance() precondition, which asserts on MSVC debug builds
+ //{
+ // auto workaround_macro = [&]() { Span<int> s{&arr[1], &arr[0]}; };
+ // CHECK_THROW(workaround_macro(), fail_fast);
+ //}
+
+ // this will fail the std::distance() precondition, which asserts on MSVC debug builds
+ //{
+ // int* p = nullptr;
+ // auto workaround_macro = [&]() { Span<int> s{&arr[0], p}; };
+ // CHECK_THROW(workaround_macro(), fail_fast);
+ //}
+
+ {
+ int* p = nullptr;
+ Span<int> s{ p, p };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+ }
+
+ {
+ int* p = nullptr;
+ Span<int, 0> s{ p, p };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+ }
+
+ // this will fail the std::distance() precondition, which asserts on MSVC debug builds
+ //{
+ // int* p = nullptr;
+ // auto workaround_macro = [&]() { Span<int> s{&arr[0], p}; };
+ // CHECK_THROW(workaround_macro(), fail_fast);
+ //}
+
+ {
+ auto s = MakeSpan(&arr[0], &arr[2]);
+ ASSERT_EQ(s.Length(), 2U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ ASSERT_EQ(s[0], 1);
+ ASSERT_EQ(s[1], 2);
+ }
+
+ {
+ auto s = MakeSpan(&arr[0], &arr[0]);
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ int* p = nullptr;
+ auto s = MakeSpan(p, p);
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), nullptr);
+ }
+}
+
+SPAN_TEST(from_array_constructor)
+{
+ int arr[5] = { 1, 2, 3, 4, 5 };
+
+ {
+ Span<int> s{ arr };
+ ASSERT_EQ(s.Length(), 5U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ Span<int, 5> s{ arr };
+ ASSERT_EQ(s.Length(), 5U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ int arr2d[2][3] = { { 1, 2, 3 }, { 4, 5, 6 } };
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<int, 6> s{ arr };
+ }
+
+ {
+ Span<int, 0> s{ arr };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ Span<int> s{ arr2d };
+ ASSERT_EQ(s.Length(), 6U);
+ ASSERT_EQ(s.data(), &arr2d[0][0]);
+ ASSERT_EQ(s[0], 1);
+ ASSERT_EQ(s[5], 6);
+ }
+
+ {
+ Span<int, 0> s{ arr2d };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), &arr2d[0][0]);
+ }
+
+ {
+ Span<int, 6> s{ arr2d };
+ }
+#endif
+ {
+ Span<int[3]> s{ &(arr2d[0]), 1 };
+ ASSERT_EQ(s.Length(), 1U);
+ ASSERT_EQ(s.data(), &arr2d[0]);
+ }
+
+ int arr3d[2][3][2] = { { { 1, 2 }, { 3, 4 }, { 5, 6 } },
+ { { 7, 8 }, { 9, 10 }, { 11, 12 } } };
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<int> s{ arr3d };
+ ASSERT_EQ(s.Length(), 12U);
+ ASSERT_EQ(s.data(), &arr3d[0][0][0]);
+ ASSERT_EQ(s[0], 1);
+ ASSERT_EQ(s[11], 12);
+ }
+
+ {
+ Span<int, 0> s{ arr3d };
+ ASSERT_EQ(s.Length(), 0U);
+ ASSERT_EQ(s.data(), &arr3d[0][0][0]);
+ }
+
+ {
+ Span<int, 11> s{ arr3d };
+ }
+
+ {
+ Span<int, 12> s{ arr3d };
+ ASSERT_EQ(s.Length(), 12U);
+ ASSERT_EQ(s.data(), &arr3d[0][0][0]);
+ ASSERT_EQ(s[0], 1);
+ ASSERT_EQ(s[5], 6);
+ }
+#endif
+ {
+ Span<int[3][2]> s{ &arr3d[0], 1 };
+ ASSERT_EQ(s.Length(), 1U);
+ ASSERT_EQ(s.data(), &arr3d[0]);
+ }
+
+ {
+ auto s = MakeSpan(arr);
+ ASSERT_EQ(s.Length(), 5U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ auto s = MakeSpan(&(arr2d[0]), 1);
+ ASSERT_EQ(s.Length(), 1U);
+ ASSERT_EQ(s.data(), &arr2d[0]);
+ }
+
+ {
+ auto s = MakeSpan(&arr3d[0], 1);
+ ASSERT_EQ(s.Length(), 1U);
+ ASSERT_EQ(s.data(), &arr3d[0]);
+ }
+}
+
+SPAN_TEST(from_dynamic_array_constructor)
+{
+ double(*arr)[3][4] = new double[100][3][4];
+
+ {
+ Span<double> s(&arr[0][0][0], 10);
+ ASSERT_EQ(s.Length(), 10U);
+ ASSERT_EQ(s.data(), &arr[0][0][0]);
+ }
+
+ {
+ auto s = MakeSpan(&arr[0][0][0], 10);
+ ASSERT_EQ(s.Length(), 10U);
+ ASSERT_EQ(s.data(), &arr[0][0][0]);
+ }
+
+ delete[] arr;
+}
+
+SPAN_TEST(from_std_array_constructor)
+{
+ std::array<int, 4> arr = { { 1, 2, 3, 4 } };
+
+ {
+ Span<int> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(s.data(), arr.data());
+
+ Span<const int> cs{ arr };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(cs.data(), arr.data());
+ }
+
+ {
+ Span<int, 4> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(s.data(), arr.data());
+
+ Span<const int, 4> cs{ arr };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(cs.data(), arr.data());
+ }
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<int, 2> s{ arr };
+ ASSERT_EQ(s.size(), 2U);
+ ASSERT_EQ(s.data(), arr.data());
+
+ Span<const int, 2> cs{ arr };
+ ASSERT_EQ(cs.size(), 2U);
+ ASSERT_EQ(cs.data(), arr.data());
+ }
+
+ {
+ Span<int, 0> s{ arr };
+ ASSERT_EQ(s.size(), 0U);
+ ASSERT_EQ(s.data(), arr.data());
+
+ Span<const int, 0> cs{ arr };
+ ASSERT_EQ(cs.size(), 0U);
+ ASSERT_EQ(cs.data(), arr.data());
+ }
+
+ {
+ Span<int, 5> s{ arr };
+ }
+
+ {
+ auto get_an_array = []() -> std::array<int, 4> { return { 1, 2, 3, 4 }; };
+ auto take_a_Span = [](Span<int> s) { static_cast<void>(s); };
+ // try to take a temporary std::array
+ take_a_Span(get_an_array());
+ }
+#endif
+
+ {
+ auto get_an_array = []() -> std::array<int, 4> {
+ return { { 1, 2, 3, 4 } };
+ };
+ auto take_a_Span = [](Span<const int> s) { static_cast<void>(s); };
+ // try to take a temporary std::array
+ take_a_Span(get_an_array());
+ }
+
+ {
+ auto s = MakeSpan(arr);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(s.data(), arr.data());
+ }
+}
+
+SPAN_TEST(from_const_std_array_constructor)
+{
+ const std::array<int, 4> arr = { { 1, 2, 3, 4 } };
+
+ {
+ Span<const int> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(s.data(), arr.data());
+ }
+
+ {
+ Span<const int, 4> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(s.data(), arr.data());
+ }
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<const int, 2> s{ arr };
+ ASSERT_EQ(s.size(), 2U);
+ ASSERT_EQ(s.data(), arr.data());
+ }
+
+ {
+ Span<const int, 0> s{ arr };
+ ASSERT_EQ(s.size(), 0U);
+ ASSERT_EQ(s.data(), arr.data());
+ }
+
+ {
+ Span<const int, 5> s{ arr };
+ }
+#endif
+
+ {
+ auto get_an_array = []() -> const std::array<int, 4> {
+ return { { 1, 2, 3, 4 } };
+ };
+ auto take_a_Span = [](Span<const int> s) { static_cast<void>(s); };
+ // try to take a temporary std::array
+ take_a_Span(get_an_array());
+ }
+
+ {
+ auto s = MakeSpan(arr);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(s.data(), arr.data());
+ }
+}
+
+SPAN_TEST(from_std_array_const_constructor)
+{
+ std::array<const int, 4> arr = { { 1, 2, 3, 4 } };
+
+ {
+ Span<const int> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(s.data(), arr.data());
+ }
+
+ {
+ Span<const int, 4> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(s.data(), arr.data());
+ }
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<const int, 2> s{ arr };
+ ASSERT_EQ(s.size(), 2U);
+ ASSERT_EQ(s.data(), arr.data());
+ }
+
+ {
+ Span<const int, 0> s{ arr };
+ ASSERT_EQ(s.size(), 0U);
+ ASSERT_EQ(s.data(), arr.data());
+ }
+
+ {
+ Span<const int, 5> s{ arr };
+ }
+
+ {
+ Span<int, 4> s{ arr };
+ }
+#endif
+
+ {
+ auto s = MakeSpan(arr);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.size()));
+ ASSERT_EQ(s.data(), arr.data());
+ }
+}
+
+SPAN_TEST(from_mozilla_array_constructor)
+{
+ mozilla::Array<int, 4> arr(1, 2, 3, 4);
+
+ {
+ Span<int> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(s.data(), &arr[0]);
+
+ Span<const int> cs{ arr };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(cs.data(), &arr[0]);
+ }
+
+ {
+ Span<int, 4> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(s.data(), &arr[0]);
+
+ Span<const int, 4> cs{ arr };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(cs.data(), &arr[0]);
+ }
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<int, 2> s{ arr };
+ ASSERT_EQ(s.size(), 2U);
+ ASSERT_EQ(s.data(), &arr[0]);
+
+ Span<const int, 2> cs{ arr };
+ ASSERT_EQ(cs.size(), 2U);
+ ASSERT_EQ(cs.data(), &arr[0]);
+ }
+
+ {
+ Span<int, 0> s{ arr };
+ ASSERT_EQ(s.size(), 0U);
+ ASSERT_EQ(s.data(), &arr[0]);
+
+ Span<const int, 0> cs{ arr };
+ ASSERT_EQ(cs.size(), 0U);
+ ASSERT_EQ(cs.data(), &arr[0]);
+ }
+
+ {
+ Span<int, 5> s{ arr };
+ }
+
+ {
+ auto get_an_array = []() -> mozilla::Array<int, 4> {
+ return { 1, 2, 3, 4 };
+ };
+ auto take_a_Span = [](Span<int> s) { static_cast<void>(s); };
+ // try to take a temporary mozilla::Array
+ take_a_Span(get_an_array());
+ }
+#endif
+
+ {
+ auto get_an_array = []() -> mozilla::Array<int, 4> {
+ return { 1, 2, 3, 4 };
+ };
+ auto take_a_Span = [](Span<const int> s) { static_cast<void>(s); };
+ // try to take a temporary mozilla::Array
+ take_a_Span(get_an_array());
+ }
+
+ {
+ auto s = MakeSpan(arr);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+}
+
+SPAN_TEST(from_const_mozilla_array_constructor)
+{
+ const mozilla::Array<int, 4> arr(1, 2, 3, 4);
+
+ {
+ Span<const int> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ Span<const int, 4> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<const int, 2> s{ arr };
+ ASSERT_EQ(s.size(), 2U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ Span<const int, 0> s{ arr };
+ ASSERT_EQ(s.size(), 0U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ Span<const int, 5> s{ arr };
+ }
+#endif
+
+#if 0
+ {
+ auto get_an_array = []() -> const mozilla::Array<int, 4> {
+ return { 1, 2, 3, 4 };
+ };
+ auto take_a_Span = [](Span<const int> s) { static_cast<void>(s); };
+ // try to take a temporary mozilla::Array
+ take_a_Span(get_an_array());
+ }
+#endif
+
+ {
+ auto s = MakeSpan(arr);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+}
+
+SPAN_TEST(from_mozilla_array_const_constructor)
+{
+ mozilla::Array<const int, 4> arr(1, 2, 3, 4);
+
+ {
+ Span<const int> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ Span<const int, 4> s{ arr };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<const int, 2> s{ arr };
+ ASSERT_EQ(s.size(), 2U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ Span<const int, 0> s{ arr };
+ ASSERT_EQ(s.size(), 0U);
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+
+ {
+ Span<const int, 5> s{ arr };
+ }
+
+ {
+ Span<int, 4> s{ arr };
+ }
+#endif
+
+ {
+ auto s = MakeSpan(arr);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(arr.cend() - arr.cbegin()));
+ ASSERT_EQ(s.data(), &arr[0]);
+ }
+}
+
+SPAN_TEST(from_container_constructor)
+{
+ std::vector<int> v = { 1, 2, 3 };
+ const std::vector<int> cv = v;
+
+ {
+ AssertSpanOfThreeInts(v);
+
+ Span<int> s{ v };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(v.size()));
+ ASSERT_EQ(s.data(), v.data());
+
+ Span<const int> cs{ v };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(v.size()));
+ ASSERT_EQ(cs.data(), v.data());
+ }
+
+ std::string str = "hello";
+ const std::string cstr = "hello";
+
+ {
+#ifdef CONFIRM_COMPILATION_ERRORS
+ Span<char> s{ str };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(str.size()));
+ ASSERT_EQ(s.data(), str.data());
+#endif
+ Span<const char> cs{ str };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(str.size()));
+ ASSERT_EQ(cs.data(), str.data());
+ }
+
+ {
+#ifdef CONFIRM_COMPILATION_ERRORS
+ Span<char> s{ cstr };
+#endif
+ Span<const char> cs{ cstr };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(cstr.size()));
+ ASSERT_EQ(cs.data(), cstr.data());
+ }
+
+ {
+#ifdef CONFIRM_COMPILATION_ERRORS
+ auto get_temp_vector = []() -> std::vector<int> { return {}; };
+ auto use_Span = [](Span<int> s) { static_cast<void>(s); };
+ use_Span(get_temp_vector());
+#endif
+ }
+
+ {
+ auto get_temp_vector = []() -> std::vector<int> { return {}; };
+ auto use_Span = [](Span<const int> s) { static_cast<void>(s); };
+ use_Span(get_temp_vector());
+ }
+
+ {
+#ifdef CONFIRM_COMPILATION_ERRORS
+ auto get_temp_string = []() -> std::string { return {}; };
+ auto use_Span = [](Span<char> s) { static_cast<void>(s); };
+ use_Span(get_temp_string());
+#endif
+ }
+
+ {
+ auto get_temp_string = []() -> std::string { return {}; };
+ auto use_Span = [](Span<const char> s) { static_cast<void>(s); };
+ use_Span(get_temp_string());
+ }
+
+ {
+#ifdef CONFIRM_COMPILATION_ERRORS
+ auto get_temp_vector = []() -> const std::vector<int> { return {}; };
+ auto use_Span = [](Span<const char> s) { static_cast<void>(s); };
+ use_Span(get_temp_vector());
+#endif
+ }
+
+ {
+ auto get_temp_string = []() -> const std::string { return {}; };
+ auto use_Span = [](Span<const char> s) { static_cast<void>(s); };
+ use_Span(get_temp_string());
+ }
+
+ {
+#ifdef CONFIRM_COMPILATION_ERRORS
+ std::map<int, int> m;
+ Span<int> s{ m };
+#endif
+ }
+
+ {
+ auto s = MakeSpan(v);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(v.size()));
+ ASSERT_EQ(s.data(), v.data());
+
+ auto cs = MakeSpan(cv);
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(cv.size()));
+ ASSERT_EQ(cs.data(), cv.data());
+ }
+}
+
+SPAN_TEST(from_xpcom_collections)
+{
+ {
+ nsTArray<int> v;
+ v.AppendElement(1);
+ v.AppendElement(2);
+ v.AppendElement(3);
+
+ AssertSpanOfThreeInts(v);
+
+ Span<int> s{ v };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(s.data(), v.Elements());
+ ASSERT_EQ(s[2], 3);
+
+ Span<const int> cs{ v };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(cs.data(), v.Elements());
+ ASSERT_EQ(cs[2], 3);
+ }
+ {
+ nsTArray<int> v;
+ v.AppendElement(1);
+ v.AppendElement(2);
+ v.AppendElement(3);
+
+ AssertSpanOfThreeInts(v);
+
+ auto s = MakeSpan(v);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(s.data(), v.Elements());
+ ASSERT_EQ(s[2], 3);
+ }
+ {
+ AutoTArray<int, 5> v;
+ v.AppendElement(1);
+ v.AppendElement(2);
+ v.AppendElement(3);
+
+ AssertSpanOfThreeInts(v);
+
+ Span<int> s{ v };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(s.data(), v.Elements());
+ ASSERT_EQ(s[2], 3);
+
+ Span<const int> cs{ v };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(cs.data(), v.Elements());
+ ASSERT_EQ(cs[2], 3);
+ }
+ {
+ AutoTArray<int, 5> v;
+ v.AppendElement(1);
+ v.AppendElement(2);
+ v.AppendElement(3);
+
+ AssertSpanOfThreeInts(v);
+
+ auto s = MakeSpan(v);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(s.data(), v.Elements());
+ ASSERT_EQ(s[2], 3);
+ }
+ {
+ FallibleTArray<int> v;
+ *(v.AppendElement(fallible)) = 1;
+ *(v.AppendElement(fallible)) = 2;
+ *(v.AppendElement(fallible)) = 3;
+
+ AssertSpanOfThreeInts(v);
+
+ Span<int> s{ v };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(s.data(), v.Elements());
+ ASSERT_EQ(s[2], 3);
+
+ Span<const int> cs{ v };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(cs.data(), v.Elements());
+ ASSERT_EQ(cs[2], 3);
+ }
+ {
+ FallibleTArray<int> v;
+ *(v.AppendElement(fallible)) = 1;
+ *(v.AppendElement(fallible)) = 2;
+ *(v.AppendElement(fallible)) = 3;
+
+ AssertSpanOfThreeInts(v);
+
+ auto s = MakeSpan(v);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(s.data(), v.Elements());
+ ASSERT_EQ(s[2], 3);
+ }
+ {
+ nsAutoString str;
+ str.AssignLiteral("abc");
+
+ AssertSpanOfThreeChar16s(str);
+ AssertSpanOfThreeChar16sViaString(str);
+
+ Span<char16_t> s{ str };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(str.Length()));
+ ASSERT_EQ(s.data(), str.BeginWriting());
+ ASSERT_EQ(s[2], 'c');
+
+ Span<const char16_t> cs{ str };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(str.Length()));
+ ASSERT_EQ(cs.data(), str.BeginReading());
+ ASSERT_EQ(cs[2], 'c');
+ }
+ {
+ nsAutoString str;
+ str.AssignLiteral("abc");
+
+ AssertSpanOfThreeChar16s(str);
+ AssertSpanOfThreeChar16sViaString(str);
+
+ auto s = MakeSpan(str);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(str.Length()));
+ ASSERT_EQ(s.data(), str.BeginWriting());
+ ASSERT_EQ(s[2], 'c');
+ }
+ {
+ nsAutoCString str;
+ str.AssignLiteral("abc");
+
+ AssertSpanOfThreeChars(str);
+ AssertSpanOfThreeCharsViaString(str);
+
+ Span<uint8_t> s{ str };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(str.Length()));
+ ASSERT_EQ(s.data(), reinterpret_cast<uint8_t*>(str.BeginWriting()));
+ ASSERT_EQ(s[2], 'c');
+
+ Span<const uint8_t> cs{ str };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(str.Length()));
+ ASSERT_EQ(cs.data(), reinterpret_cast<const uint8_t*>(str.BeginReading()));
+ ASSERT_EQ(cs[2], 'c');
+ }
+ {
+ nsAutoCString str;
+ str.AssignLiteral("abc");
+
+ AssertSpanOfThreeChars(str);
+ AssertSpanOfThreeCharsViaString(str);
+
+ auto s = MakeSpan(str);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(str.Length()));
+ ASSERT_EQ(s.data(), str.BeginWriting());
+ ASSERT_EQ(s[2], 'c');
+ }
+ {
+ nsTArray<int> v;
+ v.AppendElement(1);
+ v.AppendElement(2);
+ v.AppendElement(3);
+
+ Range<int> r(v.Elements(), v.Length());
+
+ AssertSpanOfThreeInts(r);
+
+ Span<int> s{ r };
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(s.data(), v.Elements());
+ ASSERT_EQ(s[2], 3);
+
+ Span<const int> cs{ r };
+ ASSERT_EQ(cs.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(cs.data(), v.Elements());
+ ASSERT_EQ(cs[2], 3);
+ }
+ {
+ nsTArray<int> v;
+ v.AppendElement(1);
+ v.AppendElement(2);
+ v.AppendElement(3);
+
+ Range<int> r(v.Elements(), v.Length());
+
+ AssertSpanOfThreeInts(r);
+
+ auto s = MakeSpan(r);
+ ASSERT_EQ(s.size(), narrow_cast<size_t>(v.Length()));
+ ASSERT_EQ(s.data(), v.Elements());
+ ASSERT_EQ(s[2], 3);
+ }
+}
+
+SPAN_TEST(from_cstring)
+{
+ {
+ const char* str = "abc";
+
+ auto cs = MakeCStringSpan(str);
+ ASSERT_EQ(cs.size(), 3U);
+ ASSERT_EQ(cs.data(), str);
+ ASSERT_EQ(cs[2], 'c');
+ }
+}
+
+SPAN_TEST(from_convertible_Span_constructor){
+ {
+ Span<DerivedClass> avd;
+ Span<const DerivedClass> avcd = avd;
+ static_cast<void>(avcd);
+ }
+
+ {
+#ifdef CONFIRM_COMPILATION_ERRORS
+ Span<DerivedClass> avd;
+ Span<BaseClass> avb = avd;
+ static_cast<void>(avb);
+#endif
+ }
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<int> s;
+ Span<unsigned int> s2 = s;
+ static_cast<void>(s2);
+ }
+
+ {
+ Span<int> s;
+ Span<const unsigned int> s2 = s;
+ static_cast<void>(s2);
+ }
+
+ {
+ Span<int> s;
+ Span<short> s2 = s;
+ static_cast<void>(s2);
+ }
+#endif
+}
+
+SPAN_TEST(copy_move_and_assignment)
+{
+ Span<int> s1;
+ ASSERT_TRUE(s1.empty());
+
+ int arr[] = { 3, 4, 5 };
+
+ Span<const int> s2 = arr;
+ ASSERT_EQ(s2.Length(), 3U);
+ ASSERT_EQ(s2.data(), &arr[0]);
+
+ s2 = s1;
+ ASSERT_TRUE(s2.empty());
+
+ auto get_temp_Span = [&]() -> Span<int> { return { &arr[1], 2 }; };
+ auto use_Span = [&](Span<const int> s) {
+ ASSERT_EQ(s.Length(), 2U);
+ ASSERT_EQ(s.data(), &arr[1]);
+ };
+ use_Span(get_temp_Span());
+
+ s1 = get_temp_Span();
+ ASSERT_EQ(s1.Length(), 2U);
+ ASSERT_EQ(s1.data(), &arr[1]);
+}
+
+SPAN_TEST(first)
+{
+ int arr[5] = { 1, 2, 3, 4, 5 };
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.First<2>().Length(), 2U);
+ ASSERT_EQ(av.First(2).Length(), 2U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.First<0>().Length(), 0U);
+ ASSERT_EQ(av.First(0).Length(), 0U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.First<5>().Length(), 5U);
+ ASSERT_EQ(av.First(5).Length(), 5U);
+ }
+
+#if 0
+ {
+ Span<int, 5> av = arr;
+#ifdef CONFIRM_COMPILATION_ERRORS
+ ASSERT_EQ(av.First<6>().Length() , 6U);
+ ASSERT_EQ(av.First<-1>().Length() , -1);
+#endif
+ CHECK_THROW(av.First(6).Length(), fail_fast);
+ }
+#endif
+
+ {
+ Span<int> av;
+ ASSERT_EQ(av.First<0>().Length(), 0U);
+ ASSERT_EQ(av.First(0).Length(), 0U);
+ }
+}
+
+SPAN_TEST(last)
+{
+ int arr[5] = { 1, 2, 3, 4, 5 };
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.Last<2>().Length(), 2U);
+ ASSERT_EQ(av.Last(2).Length(), 2U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.Last<0>().Length(), 0U);
+ ASSERT_EQ(av.Last(0).Length(), 0U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.Last<5>().Length(), 5U);
+ ASSERT_EQ(av.Last(5).Length(), 5U);
+ }
+
+#if 0
+ {
+ Span<int, 5> av = arr;
+#ifdef CONFIRM_COMPILATION_ERRORS
+ ASSERT_EQ(av.Last<6>().Length() , 6U);
+#endif
+ CHECK_THROW(av.Last(6).Length(), fail_fast);
+ }
+#endif
+
+ {
+ Span<int> av;
+ ASSERT_EQ(av.Last<0>().Length(), 0U);
+ ASSERT_EQ(av.Last(0).Length(), 0U);
+ }
+}
+
+SPAN_TEST(from_to)
+{
+ int arr[5] = { 1, 2, 3, 4, 5 };
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.From(3).Length(), 2U);
+ ASSERT_EQ(av.From(2)[1], 4);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.From(5).Length(), 0U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.From(0).Length(), 5U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.To(3).Length(), 3U);
+ ASSERT_EQ(av.To(3)[1], 2);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.To(0).Length(), 0U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.To(5).Length(), 5U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.FromTo(1, 4).Length(), 3U);
+ ASSERT_EQ(av.FromTo(1, 4)[1], 3);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.FromTo(2, 2).Length(), 0U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.FromTo(0, 5).Length(), 5U);
+ }
+}
+
+SPAN_TEST(Subspan)
+{
+ int arr[5] = { 1, 2, 3, 4, 5 };
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ((av.Subspan<2, 2>().Length()), 2U);
+ ASSERT_EQ(av.Subspan(2, 2).Length(), 2U);
+ ASSERT_EQ(av.Subspan(2, 3).Length(), 3U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ((av.Subspan<0, 0>().Length()), 0U);
+ ASSERT_EQ(av.Subspan(0, 0).Length(), 0U);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ((av.Subspan<0, 5>().Length()), 5U);
+ ASSERT_EQ(av.Subspan(0, 5).Length(), 5U);
+ CHECK_THROW(av.Subspan(0, 6).Length(), fail_fast);
+ CHECK_THROW(av.Subspan(1, 5).Length(), fail_fast);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ((av.Subspan<4, 0>().Length()), 0U);
+ ASSERT_EQ(av.Subspan(4, 0).Length(), 0U);
+ ASSERT_EQ(av.Subspan(5, 0).Length(), 0U);
+ CHECK_THROW(av.Subspan(6, 0).Length(), fail_fast);
+ }
+
+ {
+ Span<int> av;
+ ASSERT_EQ((av.Subspan<0, 0>().Length()), 0U);
+ ASSERT_EQ(av.Subspan(0, 0).Length(), 0U);
+ CHECK_THROW((av.Subspan<1, 0>().Length()), fail_fast);
+ }
+
+ {
+ Span<int> av;
+ ASSERT_EQ(av.Subspan(0).Length(), 0U);
+ CHECK_THROW(av.Subspan(1).Length(), fail_fast);
+ }
+
+ {
+ Span<int> av = arr;
+ ASSERT_EQ(av.Subspan(0).Length(), 5U);
+ ASSERT_EQ(av.Subspan(1).Length(), 4U);
+ ASSERT_EQ(av.Subspan(4).Length(), 1U);
+ ASSERT_EQ(av.Subspan(5).Length(), 0U);
+ CHECK_THROW(av.Subspan(6).Length(), fail_fast);
+ auto av2 = av.Subspan(1);
+ for (int i = 0; i < 4; ++i)
+ ASSERT_EQ(av2[i], i + 2);
+ }
+
+ {
+ Span<int, 5> av = arr;
+ ASSERT_EQ(av.Subspan(0).Length(), 5U);
+ ASSERT_EQ(av.Subspan(1).Length(), 4U);
+ ASSERT_EQ(av.Subspan(4).Length(), 1U);
+ ASSERT_EQ(av.Subspan(5).Length(), 0U);
+ CHECK_THROW(av.Subspan(6).Length(), fail_fast);
+ auto av2 = av.Subspan(1);
+ for (int i = 0; i < 4; ++i)
+ ASSERT_EQ(av2[i], i + 2);
+ }
+}
+
+SPAN_TEST(at_call)
+{
+ int arr[4] = { 1, 2, 3, 4 };
+
+ {
+ Span<int> s = arr;
+ ASSERT_EQ(s.at(0), 1);
+ CHECK_THROW(s.at(5), fail_fast);
+ }
+
+ {
+ int arr2d[2] = { 1, 6 };
+ Span<int, 2> s = arr2d;
+ ASSERT_EQ(s.at(0), 1);
+ ASSERT_EQ(s.at(1), 6);
+ CHECK_THROW(s.at(2), fail_fast);
+ }
+}
+
+SPAN_TEST(operator_function_call)
+{
+ int arr[4] = { 1, 2, 3, 4 };
+
+ {
+ Span<int> s = arr;
+ ASSERT_EQ(s(0), 1);
+ CHECK_THROW(s(5), fail_fast);
+ }
+
+ {
+ int arr2d[2] = { 1, 6 };
+ Span<int, 2> s = arr2d;
+ ASSERT_EQ(s(0), 1);
+ ASSERT_EQ(s(1), 6);
+ CHECK_THROW(s(2), fail_fast);
+ }
+}
+
+SPAN_TEST(iterator_default_init)
+{
+ Span<int>::iterator it1;
+ Span<int>::iterator it2;
+ ASSERT_EQ(it1, it2);
+}
+
+SPAN_TEST(const_iterator_default_init)
+{
+ Span<int>::const_iterator it1;
+ Span<int>::const_iterator it2;
+ ASSERT_EQ(it1, it2);
+}
+
+SPAN_TEST(iterator_conversions)
+{
+ Span<int>::iterator badIt;
+ Span<int>::const_iterator badConstIt;
+ ASSERT_EQ(badIt, badConstIt);
+
+ int a[] = { 1, 2, 3, 4 };
+ Span<int> s = a;
+
+ auto it = s.begin();
+ auto cit = s.cbegin();
+
+ ASSERT_EQ(it, cit);
+ ASSERT_EQ(cit, it);
+
+ Span<int>::const_iterator cit2 = it;
+ ASSERT_EQ(cit2, cit);
+
+ Span<int>::const_iterator cit3 = it + 4;
+ ASSERT_EQ(cit3, s.cend());
+}
+
+SPAN_TEST(iterator_comparisons)
+{
+ int a[] = { 1, 2, 3, 4 };
+ {
+ Span<int> s = a;
+ Span<int>::iterator it = s.begin();
+ auto it2 = it + 1;
+ Span<int>::const_iterator cit = s.cbegin();
+
+ ASSERT_EQ(it, cit);
+ ASSERT_EQ(cit, it);
+ ASSERT_EQ(it, it);
+ ASSERT_EQ(cit, cit);
+ ASSERT_EQ(cit, s.begin());
+ ASSERT_EQ(s.begin(), cit);
+ ASSERT_EQ(s.cbegin(), cit);
+ ASSERT_EQ(it, s.begin());
+ ASSERT_EQ(s.begin(), it);
+
+ ASSERT_NE(it, it2);
+ ASSERT_NE(it2, it);
+ ASSERT_NE(it, s.end());
+ ASSERT_NE(it2, s.end());
+ ASSERT_NE(s.end(), it);
+ ASSERT_NE(it2, cit);
+ ASSERT_NE(cit, it2);
+
+ ASSERT_LT(it, it2);
+ ASSERT_LE(it, it2);
+ ASSERT_LE(it2, s.end());
+ ASSERT_LT(it, s.end());
+ ASSERT_LE(it, cit);
+ ASSERT_LE(cit, it);
+ ASSERT_LT(cit, it2);
+ ASSERT_LE(cit, it2);
+ ASSERT_LT(cit, s.end());
+ ASSERT_LE(cit, s.end());
+
+ ASSERT_GT(it2, it);
+ ASSERT_GE(it2, it);
+ ASSERT_GT(s.end(), it2);
+ ASSERT_GE(s.end(), it2);
+ ASSERT_GT(it2, cit);
+ ASSERT_GE(it2, cit);
+ }
+}
+
+SPAN_TEST(begin_end)
+{
+ {
+ int a[] = { 1, 2, 3, 4 };
+ Span<int> s = a;
+
+ Span<int>::iterator it = s.begin();
+ Span<int>::iterator it2 = std::begin(s);
+ ASSERT_EQ(it, it2);
+
+ it = s.end();
+ it2 = std::end(s);
+ ASSERT_EQ(it, it2);
+ }
+
+ {
+ int a[] = { 1, 2, 3, 4 };
+ Span<int> s = a;
+
+ auto it = s.begin();
+ auto first = it;
+ ASSERT_EQ(it, first);
+ ASSERT_EQ(*it, 1);
+
+ auto beyond = s.end();
+ ASSERT_NE(it, beyond);
+ CHECK_THROW(*beyond, fail_fast);
+
+ ASSERT_EQ(beyond - first, 4U);
+ ASSERT_EQ(first - first, 0U);
+ ASSERT_EQ(beyond - beyond, 0U);
+
+ ++it;
+ ASSERT_EQ(it - first, 1U);
+ ASSERT_EQ(*it, 2);
+ *it = 22;
+ ASSERT_EQ(*it, 22);
+ ASSERT_EQ(beyond - it, 3U);
+
+ it = first;
+ ASSERT_EQ(it, first);
+ while (it != s.end()) {
+ *it = 5;
+ ++it;
+ }
+
+ ASSERT_EQ(it, beyond);
+ ASSERT_EQ(it - beyond, 0U);
+
+ for (auto& n : s) {
+ ASSERT_EQ(n, 5);
+ }
+ }
+}
+
+SPAN_TEST(cbegin_cend)
+{
+#if 0
+ {
+ int a[] = { 1, 2, 3, 4 };
+ Span<int> s = a;
+
+ Span<int>::const_iterator cit = s.cbegin();
+ Span<int>::const_iterator cit2 = std::cbegin(s);
+ ASSERT_EQ(cit , cit2);
+
+ cit = s.cend();
+ cit2 = std::cend(s);
+ ASSERT_EQ(cit , cit2);
+ }
+#endif
+ {
+ int a[] = { 1, 2, 3, 4 };
+ Span<int> s = a;
+
+ auto it = s.cbegin();
+ auto first = it;
+ ASSERT_EQ(it, first);
+ ASSERT_EQ(*it, 1);
+
+ auto beyond = s.cend();
+ ASSERT_NE(it, beyond);
+ CHECK_THROW(*beyond, fail_fast);
+
+ ASSERT_EQ(beyond - first, 4U);
+ ASSERT_EQ(first - first, 0U);
+ ASSERT_EQ(beyond - beyond, 0U);
+
+ ++it;
+ ASSERT_EQ(it - first, 1U);
+ ASSERT_EQ(*it, 2);
+ ASSERT_EQ(beyond - it, 3U);
+
+ int last = 0;
+ it = first;
+ ASSERT_EQ(it, first);
+ while (it != s.cend()) {
+ ASSERT_EQ(*it, last + 1);
+
+ last = *it;
+ ++it;
+ }
+
+ ASSERT_EQ(it, beyond);
+ ASSERT_EQ(it - beyond, 0U);
+ }
+}
+
+SPAN_TEST(rbegin_rend)
+{
+ {
+ int a[] = { 1, 2, 3, 4 };
+ Span<int> s = a;
+
+ auto it = s.rbegin();
+ auto first = it;
+ ASSERT_EQ(it, first);
+ ASSERT_EQ(*it, 4);
+
+ auto beyond = s.rend();
+ ASSERT_NE(it, beyond);
+ CHECK_THROW(*beyond, fail_fast);
+
+ ASSERT_EQ(beyond - first, 4U);
+ ASSERT_EQ(first - first, 0U);
+ ASSERT_EQ(beyond - beyond, 0U);
+
+ ++it;
+ ASSERT_EQ(it - first, 1U);
+ ASSERT_EQ(*it, 3);
+ *it = 22;
+ ASSERT_EQ(*it, 22);
+ ASSERT_EQ(beyond - it, 3U);
+
+ it = first;
+ ASSERT_EQ(it, first);
+ while (it != s.rend()) {
+ *it = 5;
+ ++it;
+ }
+
+ ASSERT_EQ(it, beyond);
+ ASSERT_EQ(it - beyond, 0U);
+
+ for (auto& n : s) {
+ ASSERT_EQ(n, 5);
+ }
+ }
+}
+
+SPAN_TEST(crbegin_crend)
+{
+ {
+ int a[] = { 1, 2, 3, 4 };
+ Span<int> s = a;
+
+ auto it = s.crbegin();
+ auto first = it;
+ ASSERT_EQ(it, first);
+ ASSERT_EQ(*it, 4);
+
+ auto beyond = s.crend();
+ ASSERT_NE(it, beyond);
+ CHECK_THROW(*beyond, fail_fast);
+
+ ASSERT_EQ(beyond - first, 4U);
+ ASSERT_EQ(first - first, 0U);
+ ASSERT_EQ(beyond - beyond, 0U);
+
+ ++it;
+ ASSERT_EQ(it - first, 1U);
+ ASSERT_EQ(*it, 3);
+ ASSERT_EQ(beyond - it, 3U);
+
+ it = first;
+ ASSERT_EQ(it, first);
+ int last = 5;
+ while (it != s.crend()) {
+ ASSERT_EQ(*it, last - 1);
+ last = *it;
+
+ ++it;
+ }
+
+ ASSERT_EQ(it, beyond);
+ ASSERT_EQ(it - beyond, 0U);
+ }
+}
+
+SPAN_TEST(comparison_operators)
+{
+ {
+ Span<int> s1 = nullptr;
+ Span<int> s2 = nullptr;
+ ASSERT_EQ(s1, s2);
+ ASSERT_FALSE(s1 != s2);
+ ASSERT_FALSE(s1 < s2);
+ ASSERT_LE(s1, s2);
+ ASSERT_FALSE(s1 > s2);
+ ASSERT_GE(s1, s2);
+ ASSERT_EQ(s2, s1);
+ ASSERT_FALSE(s2 != s1);
+ ASSERT_FALSE(s2 < s1);
+ ASSERT_LE(s2, s1);
+ ASSERT_FALSE(s2 > s1);
+ ASSERT_GE(s2, s1);
+ }
+
+ {
+ int arr[] = { 2, 1 };
+ Span<int> s1 = arr;
+ Span<int> s2 = arr;
+
+ ASSERT_EQ(s1, s2);
+ ASSERT_FALSE(s1 != s2);
+ ASSERT_FALSE(s1 < s2);
+ ASSERT_LE(s1, s2);
+ ASSERT_FALSE(s1 > s2);
+ ASSERT_GE(s1, s2);
+ ASSERT_EQ(s2, s1);
+ ASSERT_FALSE(s2 != s1);
+ ASSERT_FALSE(s2 < s1);
+ ASSERT_LE(s2, s1);
+ ASSERT_FALSE(s2 > s1);
+ ASSERT_GE(s2, s1);
+ }
+
+ {
+ int arr[] = { 2, 1 }; // bigger
+
+ Span<int> s1 = nullptr;
+ Span<int> s2 = arr;
+
+ ASSERT_NE(s1, s2);
+ ASSERT_NE(s2, s1);
+ ASSERT_NE(s1, s2);
+ ASSERT_NE(s2, s1);
+ ASSERT_LT(s1, s2);
+ ASSERT_FALSE(s2 < s1);
+ ASSERT_LE(s1, s2);
+ ASSERT_FALSE(s2 <= s1);
+ ASSERT_GT(s2, s1);
+ ASSERT_FALSE(s1 > s2);
+ ASSERT_GE(s2, s1);
+ ASSERT_FALSE(s1 >= s2);
+ }
+
+ {
+ int arr1[] = { 1, 2 };
+ int arr2[] = { 1, 2 };
+ Span<int> s1 = arr1;
+ Span<int> s2 = arr2;
+
+ ASSERT_EQ(s1, s2);
+ ASSERT_FALSE(s1 != s2);
+ ASSERT_FALSE(s1 < s2);
+ ASSERT_LE(s1, s2);
+ ASSERT_FALSE(s1 > s2);
+ ASSERT_GE(s1, s2);
+ ASSERT_EQ(s2, s1);
+ ASSERT_FALSE(s2 != s1);
+ ASSERT_FALSE(s2 < s1);
+ ASSERT_LE(s2, s1);
+ ASSERT_FALSE(s2 > s1);
+ ASSERT_GE(s2, s1);
+ }
+
+ {
+ int arr[] = { 1, 2, 3 };
+
+ AssertSpanOfThreeInts(arr);
+
+ Span<int> s1 = { &arr[0], 2 }; // shorter
+ Span<int> s2 = arr; // longer
+
+ ASSERT_NE(s1, s2);
+ ASSERT_NE(s2, s1);
+ ASSERT_NE(s1, s2);
+ ASSERT_NE(s2, s1);
+ ASSERT_LT(s1, s2);
+ ASSERT_FALSE(s2 < s1);
+ ASSERT_LE(s1, s2);
+ ASSERT_FALSE(s2 <= s1);
+ ASSERT_GT(s2, s1);
+ ASSERT_FALSE(s1 > s2);
+ ASSERT_GE(s2, s1);
+ ASSERT_FALSE(s1 >= s2);
+ }
+
+ {
+ int arr1[] = { 1, 2 }; // smaller
+ int arr2[] = { 2, 1 }; // bigger
+
+ Span<int> s1 = arr1;
+ Span<int> s2 = arr2;
+
+ ASSERT_NE(s1, s2);
+ ASSERT_NE(s2, s1);
+ ASSERT_NE(s1, s2);
+ ASSERT_NE(s2, s1);
+ ASSERT_LT(s1, s2);
+ ASSERT_FALSE(s2 < s1);
+ ASSERT_LE(s1, s2);
+ ASSERT_FALSE(s2 <= s1);
+ ASSERT_GT(s2, s1);
+ ASSERT_FALSE(s1 > s2);
+ ASSERT_GE(s2, s1);
+ ASSERT_FALSE(s1 >= s2);
+ }
+}
+
+SPAN_TEST(as_bytes)
+{
+ int a[] = { 1, 2, 3, 4 };
+
+ {
+ Span<const int> s = a;
+ ASSERT_EQ(s.Length(), 4U);
+ Span<const uint8_t> bs = AsBytes(s);
+ ASSERT_EQ(static_cast<const void*>(bs.data()),
+ static_cast<const void*>(s.data()));
+ ASSERT_EQ(bs.Length(), s.LengthBytes());
+ }
+
+ {
+ Span<int> s;
+ auto bs = AsBytes(s);
+ ASSERT_EQ(bs.Length(), s.Length());
+ ASSERT_EQ(bs.Length(), 0U);
+ ASSERT_EQ(bs.size_bytes(), 0U);
+ ASSERT_EQ(static_cast<const void*>(bs.data()),
+ static_cast<const void*>(s.data()));
+ ASSERT_EQ(bs.data(), nullptr);
+ }
+
+ {
+ Span<int> s = a;
+ auto bs = AsBytes(s);
+ ASSERT_EQ(static_cast<const void*>(bs.data()),
+ static_cast<const void*>(s.data()));
+ ASSERT_EQ(bs.Length(), s.LengthBytes());
+ }
+}
+
+SPAN_TEST(as_writable_bytes)
+{
+ int a[] = { 1, 2, 3, 4 };
+
+ {
+#ifdef CONFIRM_COMPILATION_ERRORS
+ // you should not be able to get writeable bytes for const objects
+ Span<const int> s = a;
+ ASSERT_EQ(s.Length(), 4U);
+ Span<const byte> bs = AsWritableBytes(s);
+ ASSERT_EQ(static_cast<void*>(bs.data()), static_cast<void*>(s.data()));
+ ASSERT_EQ(bs.Length(), s.LengthBytes());
+#endif
+ }
+
+ {
+ Span<int> s;
+ auto bs = AsWritableBytes(s);
+ ASSERT_EQ(bs.Length(), s.Length());
+ ASSERT_EQ(bs.Length(), 0U);
+ ASSERT_EQ(bs.size_bytes(), 0U);
+ ASSERT_EQ(static_cast<void*>(bs.data()), static_cast<void*>(s.data()));
+ ASSERT_EQ(bs.data(), nullptr);
+ }
+
+ {
+ Span<int> s = a;
+ auto bs = AsWritableBytes(s);
+ ASSERT_EQ(static_cast<void*>(bs.data()), static_cast<void*>(s.data()));
+ ASSERT_EQ(bs.Length(), s.LengthBytes());
+ }
+}
+
+SPAN_TEST(fixed_size_conversions)
+{
+ int arr[] = { 1, 2, 3, 4 };
+
+ // converting to an Span from an equal size array is ok
+ Span<int, 4> s4 = arr;
+ ASSERT_EQ(s4.Length(), 4U);
+
+ // converting to dynamic_range is always ok
+ {
+ Span<int> s = s4;
+ ASSERT_EQ(s.Length(), s4.Length());
+ static_cast<void>(s);
+ }
+
+// initialization or assignment to static Span that REDUCES size is NOT ok
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<int, 2> s = arr;
+ }
+ {
+ Span<int, 2> s2 = s4;
+ static_cast<void>(s2);
+ }
+#endif
+
+#if 0
+ // even when done dynamically
+ {
+ Span<int> s = arr;
+ auto f = [&]() {
+ Span<int, 2> s2 = s;
+ static_cast<void>(s2);
+ };
+ CHECK_THROW(f(), fail_fast);
+ }
+#endif
+
+ // but doing so explicitly is ok
+
+ // you can convert statically
+ {
+ Span<int, 2> s2 = { arr, 2 };
+ static_cast<void>(s2);
+ }
+ {
+ Span<int, 1> s1 = s4.First<1>();
+ static_cast<void>(s1);
+ }
+
+ // ...or dynamically
+ {
+ // NB: implicit conversion to Span<int,1> from Span<int>
+ Span<int, 1> s1 = s4.First(1);
+ static_cast<void>(s1);
+ }
+
+#if 0
+ // initialization or assignment to static Span that requires size INCREASE is not ok.
+ int arr2[2] = {1, 2};
+#endif
+
+#ifdef CONFIRM_COMPILATION_ERRORS
+ {
+ Span<int, 4> s3 = arr2;
+ }
+ {
+ Span<int, 2> s2 = arr2;
+ Span<int, 4> s4a = s2;
+ }
+#endif
+
+#if 0
+ {
+ auto f = [&]() {
+ Span<int, 4> _s4 = {arr2, 2};
+ static_cast<void>(_s4);
+ };
+ CHECK_THROW(f(), fail_fast);
+ }
+
+ // this should fail - we are trying to assign a small dynamic Span to a fixed_size larger one
+ Span<int> av = arr2;
+ auto f = [&]() {
+ Span<int, 4> _s4 = av;
+ static_cast<void>(_s4);
+ };
+ CHECK_THROW(f(), fail_fast);
+#endif
+}
+
+#if 0
+ SPAN_TEST(interop_with_std_regex)
+ {
+ char lat[] = { '1', '2', '3', '4', '5', '6', 'E', 'F', 'G' };
+ Span<char> s = lat;
+ auto f_it = s.begin() + 7;
+
+ std::match_results<Span<char>::iterator> match;
+
+ std::regex_match(s.begin(), s.end(), match, std::regex(".*"));
+ ASSERT_EQ(match.ready());
+ ASSERT_TRUE(!match.empty());
+ ASSERT_TRUE(match[0].matched);
+ ASSERT_TRUE(match[0].first , s.begin());
+ ASSERT_EQ(match[0].second , s.end());
+
+ std::regex_search(s.begin(), s.end(), match, std::regex("F"));
+ ASSERT_TRUE(match.ready());
+ ASSERT_TRUE(!match.empty());
+ ASSERT_TRUE(match[0].matched);
+ ASSERT_EQ(match[0].first , f_it);
+ ASSERT_EQ(match[0].second , (f_it + 1));
+ }
+
+SPAN_TEST(interop_with_gsl_at)
+{
+ int arr[5] = { 1, 2, 3, 4, 5 };
+ Span<int> s{ arr };
+ ASSERT_EQ(at(s, 0) , 1 );
+ASSERT_EQ(at(s, 1) , 2U);
+}
+#endif
+
+SPAN_TEST(default_constructible)
+{
+ ASSERT_TRUE((std::is_default_constructible<Span<int>>::value));
+ ASSERT_TRUE((std::is_default_constructible<Span<int, 0>>::value));
+ ASSERT_TRUE((!std::is_default_constructible<Span<int, 42>>::value));
+}
diff --git a/mfbt/tests/gtest/moz.build b/mfbt/tests/gtest/moz.build
new file mode 100644
index 000000000..bd559d60b
--- /dev/null
+++ b/mfbt/tests/gtest/moz.build
@@ -0,0 +1,15 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+UNIFIED_SOURCES += [
+ 'TestSpan.cpp',
+]
+
+#LOCAL_INCLUDES += [
+# '../../base',
+#]
+
+FINAL_LIBRARY = 'xul-gtest'
diff --git a/mfbt/tests/moz.build b/mfbt/tests/moz.build
index bd25ab1d0..e69de5d75 100644
--- a/mfbt/tests/moz.build
+++ b/mfbt/tests/moz.build
@@ -4,6 +4,11 @@
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+if not CONFIG['JS_STANDALONE']:
+ TEST_DIRS += [
+ 'gtest',
+ ]
+
CppUnitTests([
'TestArray',
'TestArrayUtils',
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-25 17:40:53 +0000