boost::array< T, N > Class Template Reference

A container that encapsulates fixed size arrays. More...

#include <array.hpp>

Public Types
Types
typedef T	value_type
	The array value type. More...
typedef T *	iterator
	Iterator to C-style array, i.e. a pointer. More...
typedef const T *	const_iterator
	Constant iterator to array, i.e. a pointer. More...
typedef T &	reference
	Reference to value type. More...
typedef const T &	const_reference
	Constant reference to value type. More...
typedef std::size_t	size_type
	Type used to represent array size. More...
typedef std::ptrdiff_t	difference_type
	Type used to represent distance between iterators. More...
typedef std::reverse_iterator< iterator >	reverse_iterator
	Reverse array iterator - std::reverse_iterator<iterator> More...
typedef std::reverse_iterator< const_iterator >	const_reverse_iterator
	Constant reverse array iterator - std::reverse_iterator<const_iterator> More...

Public Member Functions
Iterators
iterator	begin ()
	Returns an iterator to the beginning. More...
const_iterator	begin () const
	Returns a constant iterator to the beginning. More...
const_iterator	cbegin () const
	Returns a constant iterator to the beginning. More...
iterator	end ()
	Returns an iterator to the end. More...
const_iterator	end () const
	Returns a constant iterator to the end. More...
const_iterator	cend () const
	Returns a constant iterator to the end. More...
reverse_iterator	rbegin ()
	Returns a reverse iterator to the beginning. More...
const_reverse_iterator	rbegin () const
	Returns a constant reverse iterator to the beginning. More...
const_reverse_iterator	crbegin () const
	Returns a reverse iterator to the beginning. More...
reverse_iterator	rend ()
	Returns a reverse iterator to the end. More...
const_reverse_iterator	rend () const
	Returns a constant reverse iterator to the end. More...
const_reverse_iterator	crend () const
	Returns a constant reverse iterator to the end. More...
Element access
reference	operator[] (size_type i)
	Access specified element. More...
const_reference	operator[] (size_type i) const
	Access specified element. More...
reference	at (size_type i)
	Access specified element with bounds checking. More...
const_reference	at (size_type i) const
	Access specified element with bounds checking. More...
reference	front ()
	Access the first array element. More...
constexpr const_reference	front () const
	Access the first array element. More...
reference	back ()
	Access the last array element. More...
constexpr const_reference	back () const
	Access the last array element. More...
Swap
void	swap (array< T, N > &y)
	Swaps the container contents. More...
Direct access to data
const T *	data () const
	Direct access to the underlying array. More...
T *	data ()
	Direct access to the underlying array. More...
T *	c_array ()
	Direct access to the underlying array. More...
Assignment with type conversion
template<typename T2 >
array< T, N > &	operator= (const array< T2, N > &rhs)
	Overwrites element of the array with elements of another array. More...
void	assign (const T &value)
	Assign one value to all elements. More...
void	fill (const T &value)
	Assign one value to all elements. More...

Static Public Member Functions
Capacity
static constexpr size_type	size ()
	Returns the number of elements. More...
static constexpr bool	empty ()
	Checks whether the container is empty. More...
static constexpr size_type	max_size ()
	Returns the maximum possible number of elements. More...
Check range
static constexpr bool	rangecheck (size_type i)
	Check range. More...

Public Attributes
T	elems [N]
	Underlying fixed-size array of elements of type T. More...

Detailed Description

template<class T, std::size_t N>
class boost::array< T, N >

A container that encapsulates fixed size arrays.

This class represents a container that encapsulates fixed size arrays.

It has the same semantics as a struct holding a C-style array T[N]. Unlike a C-style array, it doesn't decay to T* automatically.

The class combines the performance of a C-style array with the convenience of a standard container.

There is a special case for a zero-length array (N == 0). In that case, array.begin() == array.end(), which is some unique value.

Thread Safety

Not thread safe

Template Parameters

T	The array value type
N	The array size

See also

See Also std::vector

Member Typedef Documentation

const_iterator

template<class T , std::size_t N>

typedef const T* boost::array< T, N >::const_iterator

Constant iterator to array, i.e. a pointer.

const_reference

template<class T , std::size_t N>

typedef const T& boost::array< T, N >::const_reference

Constant reference to value type.

const_reverse_iterator

template<class T , std::size_t N>

typedef std::reverse_iterator<const_iterator> boost::array< T, N >::const_reverse_iterator

Constant reverse array iterator - std::reverse_iterator<const_iterator>

difference_type

template<class T , std::size_t N>

typedef std::ptrdiff_t boost::array< T, N >::difference_type

Type used to represent distance between iterators.

iterator

template<class T , std::size_t N>

typedef T* boost::array< T, N >::iterator

Iterator to C-style array, i.e. a pointer.

reference

template<class T , std::size_t N>

typedef T& boost::array< T, N >::reference

Reference to value type.

reverse_iterator

template<class T , std::size_t N>

typedef std::reverse_iterator<iterator> boost::array< T, N >::reverse_iterator

Reverse array iterator - std::reverse_iterator<iterator>

size_type

template<class T , std::size_t N>

typedef std::size_t boost::array< T, N >::size_type

Type used to represent array size.

value_type

template<class T , std::size_t N>

typedef T boost::array< T, N >::value_type

The array value type.

Member Function Documentation

assign()

template<class T , std::size_t N>

void boost::array< T, N >::assign

(

const T &

value

)

Assign one value to all elements.

This function assigns the same value to all arrays elements

Complexity

Linear

Note

This function is not available in std::array.

This function is a synonym for fill.

Returns

(none)

See also

See Also operator=, fill

at() [1/2]

template<class T , std::size_t N>

reference boost::array< T, N >::at

(

size_type

i

)

Access specified element with bounds checking.

This function Returns a reference to the element at specified location i, with bounds checking.

If pos is not within the range of the container, an exception of type std::out_of_range is thrown.

Complexity

Constant

Preconditions

!(i < size())

Exception Safety

std::out_of_range if !(i < size()).

Returns

Reference to the requested element.

Parameters

i	Position of the element to return

See also

See Also operator[]

at() [2/2]

template<class T , std::size_t N>

const_reference boost::array< T, N >::at

(

size_type

i

)

const

Access specified element with bounds checking.

This function Returns a reference to the element at specified location i, with bounds checking.

If pos is not within the range of the container, an exception of type std::out_of_range is thrown.

This overload gets called when this is constant.

Complexity

Constant

Preconditions

!(i < size())

Exception Safety

std::out_of_range if !(i < size()).

Returns

Reference to the requested element.

Parameters

i	Position of the element to return

See also

See Also operator[]

back() [1/2]

template<class T , std::size_t N>

reference boost::array< T, N >::back

(

)

Access the last array element.

This function returns a reference to the last element in the container.

Calling front on an empty container is undefined.

Complexity

Constant

Note

c.back() is equivalent to *stdprev(c.end())

Preconditions

!(empty())

Returns

Reference to the last array element.

See also

See Also operator[], at, begin, end

back() [2/2]

template<class T , std::size_t N>

constexpr const_reference boost::array< T, N >::back ( ) const

constexpr

Access the last array element.

This function returns a reference to the last element in the container.

Calling front on an empty container is undefined.

This overload gets called when this is constant.

Complexity

Constant

Note

c.back() is equivalent to *stdprev(c.end())

Preconditions

!(empty())

Returns

Reference to the last array element.

See also

See Also operator[], at, begin, end

begin() [1/2]

template<class T , std::size_t N>

iterator boost::array< T, N >::begin

(

)

Returns an iterator to the beginning.

This function returns an iterator to the first element of the array.

Complexity

Constant

Note

If the array is empty, the returned iterator will be equal to end()

Returns

Iterator to the first element of the array

See also

See Also end

begin() [2/2]

template<class T , std::size_t N>

const_iterator boost::array< T, N >::begin

(

)

const

Returns a constant iterator to the beginning.

This function returns a constant iterator to the first element of the array. This is the overload that gets called when this is constant.

Complexity

Constant

Note

If the array is empty, the returned iterator will be equal to end()

Returns

Iterator to the first element of the array

See also

See Also end

c_array()

template<class T , std::size_t N>

T * boost::array< T, N >::c_array

(

)

Direct access to the underlying array.

Returns pointer to the underlying array serving as element storage.

Complexity

Constant

Note

The pointer is such that range [data(); data() + size()) is always a valid range, even if the container is empty.

When the container is empty, data() is not dereferenceable.

If size() is 0, data() may or may not return a null pointer.

This function is not available in std::array

Returns

Pointer to the underlying element storage

For non-empty containers, the returned pointer compares equal to the address of the first element.

See also

See Also front, back, size

cbegin()

template<class T , std::size_t N>

const_iterator boost::array< T, N >::cbegin

(

)

const

Returns a constant iterator to the beginning.

This function returns a constant iterator to the first element of the array.

This function is usually called to provide a constant iterator when this is not constant.

Complexity

Constant

Note

If the array is empty, the returned iterator will be equal to end()

@return Iterator to the first element of the array

See also

See Also end

cend()

template<class T , std::size_t N>

const_iterator boost::array< T, N >::cend

(

)

const

Returns a constant iterator to the end.

This function returns a constant iterator to the element following the last element of the array.

This function is usually called to provide a constant iterator when this is not constant.

Complexity

Constant

Note

If the array is empty, the returned iterator will be equal to end()

Returns

Iterator to the element following the last element of the array

See also

See Also cbegin

crbegin()

template<class T , std::size_t N>

const_reverse_iterator boost::array< T, N >::crbegin

(

)

const

Returns a reverse iterator to the beginning.

Returns a reverse iterator to the first element of the reversed array.

This reverse iterator corresponds to the last element of the non-reversed array.

This function is usually called to provide a constant iterator when this is not constant.

Complexity

Constant

Note

If the array is empty, the returned iterator is equal to rend().

Returns

Reverse iterator to the first element of the reversed array

See also

See Also rend

crend()

template<class T , std::size_t N>

const_reverse_iterator boost::array< T, N >::crend

(

)

const

Returns a constant reverse iterator to the end.

Returns a reverse iterator to the element following the last element of the reversed array.

This iterator corresponds to the element preceding the first element of the non-reversed array.

This element acts as a placeholder. Attempting to access it results in undefined behavior.

This function is usually called to provide a constant iterator when this is not constant.

Complexity

Constant

Note

If the array is empty, the returned iterator is equal to rend().

Returns

Reverse iterator to the first element of the reversed array

See also

See Also rend

data() [1/2]

template<class T , std::size_t N>

T * boost::array< T, N >::data

(

)

Direct access to the underlying array.

Returns pointer to the underlying array serving as element storage.

Complexity

Constant

Note

The pointer is such that range [data(); data() + size()) is always a valid range, even if the container is empty.

When the container is empty, data() is not dereferenceable.

If size() is 0, data() may or may not return a null pointer.

Returns

Pointer to the underlying element storage

For non-empty containers, the returned pointer compares equal to the address of the first element.

See also

See Also front, back, size

data() [2/2]

template<class T , std::size_t N>

const T * boost::array< T, N >::data

(

)

const

Direct access to the underlying array.

Returns pointer to the underlying array serving as element storage.

This overload gets called when this is constant.

Complexity

Constant

Note

The pointer is such that range [data(); data() + size()) is always a valid range, even if the container is empty.

When the container is empty, data() is not dereferenceable.

If size() is 0, data() may or may not return a null pointer.

Returns

Pointer to the underlying element storage

For non-empty containers, the returned pointer compares equal to the address of the first element.

See also

See Also front, back, size

empty()

template<class T , std::size_t N>

static constexpr bool boost::array< T, N >::empty ( )

staticconstexpr

Checks whether the container is empty.

This function checks whether the container is empty

Complexity

Constant

Note

empty() is equivalent to begin() == end()

Returns

true if the container is empty, false otherwise

See also

See Also size, max_size

end() [1/2]

template<class T , std::size_t N>

iterator boost::array< T, N >::end

(

)

Returns an iterator to the end.

This function returns an iterator to the element following the last element of the array

Complexity

Constant

Note

If the array is empty, the returned iterator will be equal to end()

Returns

Iterator to the element following the last element of the array

See also

See Also begin

end() [2/2]

template<class T , std::size_t N>

const_iterator boost::array< T, N >::end

(

)

const

Returns a constant iterator to the end.

This function returns a constant iterator to the first element of the array.

This function overload gets called when this is constant.

Complexity

Constant

Note

If the array is empty, the returned iterator will be equal to end()

Returns

Iterator to the element following the last element of the array

See also

See Also begin

fill()

template<class T , std::size_t N>

void boost::array< T, N >::fill

(

const T &

value

)

Assign one value to all elements.

This function assigns the same value to all arrays elements

Complexity

Linear

Note

This function is not available in std::array

Returns

(none)

See also

See Also operator=

front() [1/2]

template<class T , std::size_t N>

reference boost::array< T, N >::front

(

)

Access the first array element.

This function returns a reference to the first element in the container.

Calling front on an empty container is undefined.

Complexity

Constant

Note

c.front() is equivalent to *c.begin()

Preconditions

!(empty())

Returns

Reference to the first array element.

See also

See Also operator[], at, begin, end

front() [2/2]

template<class T , std::size_t N>

constexpr const_reference boost::array< T, N >::front ( ) const

constexpr

Access the first array element.

This function returns a reference to the first element in the container.

Calling front on an empty container is undefined.

This overload gets called when this is constant.

Complexity

Constant

Note

c.front() is equivalent to *c.begin()

Preconditions

!(empty())

Returns

Reference to the first array element.

See also

See Also operator[], at, begin, end

max_size()

template<class T , std::size_t N>

static constexpr size_type boost::array< T, N >::max_size ( )

staticconstexpr

Returns the maximum possible number of elements.

Returns the maximum number of elements the container is able to hold due to system or library implementation limitations

Complexity

Constant

Note

Because array<T, N> is a fixed-size container, the value returned by max_size() is equivalent to size()

Returns

Maximum number of elements

See also

See Also size, empty

operator=()

template<class T , std::size_t N>

template<typename T2 >

array< T, N > & boost::array< T, N >::operator=

(

const array< T2, N > &

rhs

)

Overwrites element of the array with elements of another array.

This function overwrites every element of the this array with the corresponding elements of another array

Complexity

Linear

Returns

Pointer to this array

See also

See Also assign

operator[]() [1/2]

template<class T , std::size_t N>

reference boost::array< T, N >::operator[]

(

size_type

i

)

Access specified element.

This function Returns a reference to the element at specified location i.

No bounds checking is performed.

Complexity

Constant

Preconditions

!(i < size())

Note

Unlike std::map::operator[], this operator never inserts a new element into the container.

Accessing a nonexistent element through this operator is undefined behavior.

Returns

Reference to the requested element.

Parameters

i	Position of the element to return

See also

See Also at

operator[]() [2/2]

template<class T , std::size_t N>

const_reference boost::array< T, N >::operator[]

(

size_type

i

)

const

Access specified element.

This function Returns a reference to the element at specified location i.

No bounds checking is performed.

This overload gets called when this is constant.

Complexity

Constant

Preconditions

!(i < size())

Note

Unlike std::map::operator[], this operator never inserts a new element into the container.

Accessing a nonexistent element through this operator is undefined behavior.

Returns

Reference to the requested element.

Parameters

i	Position of the element to return

See also

See Also at

rangecheck()

template<class T , std::size_t N>

static constexpr bool boost::array< T, N >::rangecheck ( size_type  i )

staticconstexpr

Check range.

This function checks if i in the valid range for the array.

This function may be private because it is static.

Complexity

Constant

Exception Safety

Throws std::out_of_range if i is not in the valid range.

Note

This function is not available in std::array

Returns

True if i is in the valid range for the array

See also

See Also size, empty

rbegin() [1/2]

template<class T , std::size_t N>

reverse_iterator boost::array< T, N >::rbegin

(

)

Returns a reverse iterator to the beginning.

Returns a reverse iterator to the first element of the reversed array.

This reverse iterator corresponds to the last element of the non-reversed array.

Complexity

Constant

Note

If the array is empty, the returned iterator is equal to rend().

Returns

Reverse iterator to the first element of the reversed array

See also

See Also rend

rbegin() [2/2]

template<class T , std::size_t N>

const_reverse_iterator boost::array< T, N >::rbegin

(

)

const

Returns a constant reverse iterator to the beginning.

Returns a reverse iterator to the first element of the reversed array.

This reverse iterator corresponds to the last element of the non-reversed array.

This function overload gets called when this is constant.

Complexity

Constant

Note

If the array is empty, the returned iterator is equal to rend().

Returns

Reverse iterator to the first element of the reversed array

See also

See Also rend

rend() [1/2]

template<class T , std::size_t N>

reverse_iterator boost::array< T, N >::rend

(

)

Returns a reverse iterator to the end.

Returns a reverse iterator to the element following the last element of the reversed array.

This iterator corresponds to the element preceding the first element of the non-reversed array.

This element acts as a placeholder. Attempting to access it results in undefined behavior.

Complexity

Constant

Note

If the array is empty, the returned iterator is equal to rend().

Returns

Reverse iterator to the first element of the reversed array

See also

See Also rend

rend() [2/2]

template<class T , std::size_t N>

const_reverse_iterator boost::array< T, N >::rend

(

)

const

Returns a constant reverse iterator to the end.

Returns a reverse iterator to the element following the last element of the reversed array.

This iterator corresponds to the element preceding the first element of the non-reversed array.

This element acts as a placeholder. Attempting to access it results in undefined behavior.

This function overload gets called when this is constant.

Complexity

Constant

Note

If the array is empty, the returned iterator is equal to rend().

Returns

Reverse iterator to the first element of the reversed array

See also

See Also rend

size()

template<class T , std::size_t N>

static constexpr size_type boost::array< T, N >::size ( )

staticconstexpr

Returns the number of elements.

This function returns the number of elements in the container.

Complexity

Constant

Note

size() is equivalent to std::distance(begin(), end())

Returns

The number of elements in the container

See also

See Also empty, max_size

swap()

template<class T , std::size_t N>

void boost::array< T, N >::swap

(

array< T, N > &

y

)

Swaps the container contents.

Exchanges the contents of the container with those of other.

This function does not cause iterators and references to associate with the other container.

Complexity

Linear

Note

Because array<T, N> is not dynamically allocated, this operation has linear complexity.

Returns

(none)

Parameters

y	container to exchange the contents with

See also

See Also fill, std::swap

Member Data Documentation

elems

template<class T , std::size_t N>

T boost::array< T, N >::elems[N]

Underlying fixed-size array of elements of type T.