[support.initlist] (original) (raw)

17 Language support library [support]

17.11 Initializer lists [support.initlist]

17.11.2 Header <initializer_list> synopsis [initializer.list.syn]

namespace std { template<class E> class initializer_list { public: using value_type = E;using reference = const E&;using const_reference = const E&;using size_type = size_t;using iterator = const E*;using const_iterator = const E*;constexpr initializer_list() noexcept;constexpr size_t size() const noexcept; constexpr const E* begin() const noexcept; constexpr const E* end() const noexcept; };template<class E> constexpr const E* begin(initializer_list<E> il) noexcept;template<class E> constexpr const E* end(initializer_list<E> il) noexcept;}

An object of type initializer_list<E> provides access to an array of objects of type const E.

[Note 1:

A pair of pointers or a pointer plus a length would be obvious representations for initializer_list.

initializer_list is used to implement initializer lists as specified in [dcl.init.list].

Copying an initializer_list does not copy the underlying elements.

— _end note_]

If an explicit specialization or partial specialization ofinitializer_list is declared, the program is ill-formed.

17.11.3 Initializer list constructors [support.initlist.cons]

constexpr initializer_list() noexcept;

Postconditions: size() == 0.

17.11.4 Initializer list access [support.initlist.access]

constexpr const E* begin() const noexcept;

Returns: A pointer to the beginning of the array.

If size() == 0 the values of begin() and end() are unspecified but they shall be identical.

constexpr const E* end() const noexcept;

Returns: begin() + size().

constexpr size_t size() const noexcept;

Returns: The number of elements in the array.

Complexity: Constant time.

17.11.5 Initializer list range access [support.initlist.range]

template<class E> constexpr const E* begin(initializer_list<E> il) noexcept;

template<class E> constexpr const E* end(initializer_list<E> il) noexcept;