12 #include <type_traits>
15 #define CONSTEXPR_IF_NOT_DEBUG
16 #define ASSERT_IF_DEBUG(x) assert((x))
18 #define CONSTEXPR_IF_NOT_DEBUG constexpr
19 #define ASSERT_IF_DEBUG(x)
22 #if defined(__clang__)
23 #if __has_attribute(lifetimebound)
24 #define SPAN_ATTR_LIFETIMEBOUND [[clang::lifetimebound]]
26 #define SPAN_ATTR_LIFETIMEBOUND
29 #define SPAN_ATTR_LIFETIMEBOUND
118 template <
typename T,
typename std::enable_if<std::is_convertible<T (*)[], C (*)[]>::value,
int>::type = 0>
126 template <
typename T,
typename std::enable_if<std::is_convertible<T (*)[], C (*)[]>::value,
int>::type = 0>
140 template <
typename O,
typename std::enable_if<std::is_convertible<O (*)[], C (*)[]>::value,
int>::type = 0>
160 template <
typename V>
163 std::is_convertible<
typename std::remove_pointer<decltype(std::declval<V&>().
data())>::type (*)[], C (*)[]>::value &&
164 std::is_convertible<decltype(std::declval<V&>().
size()), std::size_t>::value, std::nullptr_t>::type =
nullptr)
167 template <
typename V>
170 std::is_convertible<
typename std::remove_pointer<decltype(std::declval<const V&>().
data())>::type (*)[], C (*)[]>::value &&
171 std::is_convertible<decltype(std::declval<const V&>().
size()), std::size_t>::value, std::nullptr_t>::type =
nullptr)
187 constexpr std::size_t
size() const noexcept {
return m_size; }
189 constexpr
bool empty() const noexcept {
return size() == 0; }
216 friend constexpr
bool operator==(
const Span& a,
const Span& b) noexcept {
return a.size() == b.size() && std::equal(a.begin(), a.end(), b.begin()); }
218 friend constexpr
bool operator<(
const Span& a,
const Span& b) noexcept {
return std::lexicographical_compare(a.begin(), a.end(), b.begin(), b.end()); }
223 template <
typename O>
friend class Span;
245 template <
typename T,
typename EndOrSize>
Span(
T*, EndOrSize) ->
Span<T>;
254 template <
typename T>
265 template <
typename T>
268 return {
reinterpret_cast<const std::byte*
>(s.data()), s.
size_bytes()};
270 template <
typename T>
273 return {
reinterpret_cast<std::byte*
>(s.data()), s.size_bytes()};
276 template <
typename V>
281 template <
typename V>
288 inline unsigned char*
UCharCast(
char* c) {
return reinterpret_cast<unsigned char*
>(c); }
289 inline unsigned char*
UCharCast(
unsigned char* c) {
return c; }
290 inline unsigned char*
UCharCast(
signed char* c) {
return reinterpret_cast<unsigned char*
>(c); }
291 inline unsigned char*
UCharCast(std::byte* c) {
return reinterpret_cast<unsigned char*
>(c); }
292 inline const unsigned char*
UCharCast(
const char* c) {
return reinterpret_cast<const unsigned char*
>(c); }
293 inline const unsigned char*
UCharCast(
const unsigned char* c) {
return c; }
294 inline const unsigned char*
UCharCast(
const signed char* c) {
return reinterpret_cast<const unsigned char*
>(c); }
295 inline const unsigned char*
UCharCast(
const std::byte* c) {
return reinterpret_cast<const unsigned char*
>(c); }
297 template <
typename B>
A Span is an object that can refer to a contiguous sequence of objects.
constexpr std::size_t size() const noexcept
constexpr friend bool operator>=(const Span &a, const Span &b) noexcept
Span & operator=(const Span &other) noexcept=default
Default assignment operator.
constexpr friend bool operator>(const Span &a, const Span &b) noexcept
CONSTEXPR_IF_NOT_DEBUG Span< C > subspan(std::size_t offset, std::size_t count) const noexcept
constexpr Span(V &other SPAN_ATTR_LIFETIMEBOUND, typename std::enable_if<!is_Span< V >::value &&std::is_convertible< typename std::remove_pointer< decltype(std::declval< V & >().data())>::type(*)[], C(*)[]>::value &&std::is_convertible< decltype(std::declval< V & >().size()), std::size_t >::value, std::nullptr_t >::type=nullptr)
Construct a Span for objects with .data() and .size() (std::string, std::array, std::vector,...
CONSTEXPR_IF_NOT_DEBUG C & back() const noexcept
constexpr Span(C(&a)[N]) noexcept
Construct a Span from an array.
constexpr Span() noexcept
CONSTEXPR_IF_NOT_DEBUG C & front() const noexcept
constexpr C * data() const noexcept
constexpr Span(T *begin, std::size_t size) noexcept
Construct a span from a begin pointer and a size.
CONSTEXPR_IF_NOT_DEBUG Span(T *begin, T *end) noexcept
Construct a span from a begin and end pointer.
constexpr C * end() const noexcept
constexpr C * begin() const noexcept
constexpr Span(const Span &) noexcept=default
Default copy constructor.
constexpr Span(const V &other SPAN_ATTR_LIFETIMEBOUND, typename std::enable_if<!is_Span< V >::value &&std::is_convertible< typename std::remove_pointer< decltype(std::declval< const V & >().data())>::type(*)[], C(*)[]>::value &&std::is_convertible< decltype(std::declval< const V & >().size()), std::size_t >::value, std::nullptr_t >::type=nullptr)
constexpr std::size_t size_bytes() const noexcept
CONSTEXPR_IF_NOT_DEBUG Span< C > last(std::size_t count) const noexcept
CONSTEXPR_IF_NOT_DEBUG Span< C > first(std::size_t count) const noexcept
CONSTEXPR_IF_NOT_DEBUG C & operator[](std::size_t pos) const noexcept
CONSTEXPR_IF_NOT_DEBUG Span< C > subspan(std::size_t offset) const noexcept
constexpr bool empty() const noexcept
constexpr friend bool operator!=(const Span &a, const Span &b) noexcept
constexpr friend bool operator==(const Span &a, const Span &b) noexcept
constexpr Span(const Span< O > &other) noexcept
Implicit conversion of spans between compatible types.
constexpr friend bool operator<(const Span &a, const Span &b) noexcept
constexpr friend bool operator<=(const Span &a, const Span &b) noexcept
#define ASSERT_IF_DEBUG(x)
#define SPAN_ATTR_LIFETIMEBOUND
constexpr auto MakeUCharSpan(V &&v) -> decltype(UCharSpanCast(Span{std::forward< V >(v)}))
Like the Span constructor, but for (const) unsigned char member types only.
std::remove_pointer_t< decltype(std::declval< T & >().data())> DataResult
Span< std::byte > AsWritableBytes(Span< T > s) noexcept
unsigned char * UCharCast(char *c)
Span(T *, EndOrSize) -> Span< T >
constexpr auto UCharSpanCast(Span< T > s) -> Span< typename std::remove_pointer< decltype(UCharCast(s.data()))>::type >
Span< const std::byte > MakeByteSpan(V &&v) noexcept
Span< const std::byte > AsBytes(Span< T > s) noexcept
#define CONSTEXPR_IF_NOT_DEBUG
Span< std::byte > MakeWritableByteSpan(V &&v) noexcept
T & SpanPopBack(Span< T > &span)
Pop the last element off a span, and return a reference to that element.