14 #define CONSTEXPR_IF_NOT_DEBUG 15 #define ASSERT_IF_DEBUG(x) assert((x)) 17 #define CONSTEXPR_IF_NOT_DEBUG constexpr 18 #define ASSERT_IF_DEBUG(x) 21 #if defined(__clang__) 22 #if __has_attribute(lifetimebound) 23 #define SPAN_ATTR_LIFETIMEBOUND [[clang::lifetimebound]] 25 #define SPAN_ATTR_LIFETIMEBOUND 28 #define SPAN_ATTR_LIFETIMEBOUND 106 constexpr
Span() noexcept : m_data(
nullptr), m_size(0) {}
113 template <typename T, typename std::enable_if<std::is_convertible<T (*)[], C (*)[]>::value,
int>::type = 0>
121 template <typename T, typename std::enable_if<std::is_convertible<T (*)[], C (*)[]>::value,
int>::type = 0>
135 template <typename O, typename std::enable_if<std::is_convertible<O (*)[], C (*)[]>::value,
int>::type = 0>
139 constexpr
Span(
const Span&) noexcept =
default;
155 template <
typename V>
158 std::is_convertible<
typename std::remove_pointer<decltype(std::declval<V&>().
data())>::type (*)[], C (*)[]>::value &&
159 std::is_convertible<decltype(std::declval<V&>().
size()), std::size_t>::value, std::nullptr_t>::type =
nullptr)
160 : m_data(other.
data()), m_size(other.
size()){}
162 template <
typename V>
163 constexpr
Span(
const V& other SPAN_ATTR_LIFETIMEBOUND,
165 std::is_convertible<
typename std::remove_pointer<decltype(std::declval<const V&>().
data())>::type (*)[], C (*)[]>::value &&
166 std::is_convertible<decltype(std::declval<const V&>().
size()), std::size_t>::value, std::nullptr_t>::type =
nullptr)
167 : m_data(other.
data()), m_size(other.
size()){}
171 constexpr C*
end() const noexcept {
return m_data +
m_size; }
180 return m_data[m_size - 1];
182 constexpr std::size_t
size() const noexcept {
return m_size; }
183 constexpr
bool empty() const noexcept {
return size() == 0; }
192 return Span<C>(m_data + offset, m_size - offset);
210 friend constexpr
bool operator==(
const Span& a,
const Span& b) noexcept {
return a.
size() == b.size() && std::equal(a.begin(), a.end(), b.begin()); }
212 friend constexpr
bool operator<(
const Span& a,
const Span& b) noexcept {
return std::lexicographical_compare(a.begin(), a.end(), b.begin(), b.end()); }
217 template <
typename O>
friend class Span;
224 template <
typename V> constexpr
auto MakeSpan(V&& v SPAN_ATTR_LIFETIMEBOUND) ->
typename std::enable_if<!std::is_lvalue_reference<V>::value,
Span<
const typename std::remove_pointer<decltype(v.data())>::type>>::type {
return std::forward<V>(v); }
226 template <
typename V> constexpr
auto MakeSpan(V& v SPAN_ATTR_LIFETIMEBOUND) ->
Span<
typename std::remove_pointer<decltype(v.data())>::type> {
return v; }
229 template <
typename T>
234 T&
back = span[size - 1];
240 inline unsigned char*
UCharCast(
char* c) {
return (
unsigned char*)c; }
241 inline unsigned char*
UCharCast(
unsigned char* c) {
return c; }
242 inline const unsigned char*
UCharCast(
const char* c) {
return (
unsigned char*)c; }
243 inline const unsigned char*
UCharCast(
const unsigned char* c) {
return c; }
CONSTEXPR_IF_NOT_DEBUG Span< C > first(std::size_t count) const noexcept
CONSTEXPR_IF_NOT_DEBUG Span< C > subspan(std::size_t offset) const noexcept
friend constexpr bool operator<(const Span &a, const Span &b) noexcept
constexpr C * end() const noexcept
constexpr Span(C(&a)[N]) noexcept
Construct a Span from an array.
friend constexpr bool operator<=(const Span &a, const Span &b) noexcept
constexpr Span(T *begin, std::size_t size) noexcept
Construct a span from a begin pointer and a size.
constexpr std::size_t size() const noexcept
constexpr Span(const Span< O > &other) noexcept
Implicit conversion of spans between compatible types.
friend constexpr bool operator>=(const Span &a, const Span &b) noexcept
friend constexpr bool operator!=(const Span &a, const Span &b) noexcept
friend constexpr bool operator==(const Span &a, const Span &b) noexcept
#define ASSERT_IF_DEBUG(x)
friend constexpr bool operator>(const Span &a, const Span &b) noexcept
CONSTEXPR_IF_NOT_DEBUG C & operator[](std::size_t pos) const noexcept
constexpr auto MakeUCharSpan(V &&v) -> decltype(UCharSpanCast(MakeSpan(std::forward< V >(v))))
Like MakeSpan, but for (const) unsigned char member types only.
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 Span() noexcept
CONSTEXPR_IF_NOT_DEBUG C & front() const noexcept
CONSTEXPR_IF_NOT_DEBUG Span(T *begin, T *end) noexcept
Construct a span from a begin and end pointer.
constexpr C * begin() const noexcept
constexpr auto UCharSpanCast(Span< T > s) -> Span< typename std::remove_pointer< decltype(UCharCast(s.data()))>::type >
constexpr C * data() const noexcept
#define CONSTEXPR_IF_NOT_DEBUG
#define SPAN_ATTR_LIFETIMEBOUND
CONSTEXPR_IF_NOT_DEBUG C & back() const noexcept
Span & operator=(const Span &other) noexcept=default
Default assignment operator.
T & SpanPopBack(Span< T > &span)
Pop the last element off a span, and return a reference to that element.
constexpr bool empty() const noexcept
unsigned char * UCharCast(char *c)
A Span is an object that can refer to a contiguous sequence of objects.
CONSTEXPR_IF_NOT_DEBUG Span< C > last(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 Span< C > subspan(std::size_t offset, std::size_t count) const noexcept
Span< A > constexpr MakeSpan(A(&a)[N])
MakeSpan for arrays: