# std::experimental::basic_string_view

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< cpp‎ | experimental

Defined in header `<experimental/string_view>` |  |
template< class CharT, class Traits = std::char_traits <CharT> > class basic_string_view; |  | (library fundamentals TS)

The class template `basic_string_view` describes an object that can refer to a constant contiguous sequence of char-like objects with the first element of the sequence at position zero.

A typical implementation holds only two members: a pointer to constant `CharT` and a size.

Several typedefs for common character types are provided:

Defined in header `<experimental/string_view>`
Type | Definition
std::experimental::string_view | std::experimental::basic_string_view<char>
std::experimental::wstring_view | std::experimental::basic_string_view<wchar_t>
std::experimental::u16string_view | std::experimental::basic_string_view<char16_t>
std::experimental::u32string_view | std::experimental::basic_string_view<char32_t>

### Template parameters

CharT | - | character type
Traits | - | traits class specifying the operations on the character type

### Member types

Member type | Definition
`traits_type` | `Traits`
`value_type` | `CharT`
`pointer` | `CharT*`
`const_pointer` | `const CharT*`
`reference` | `CharT&`
`const_reference` | `const CharT&`
`const_iterator` | implementation-defined LegacyRandomAccessIterator
`iterator` | `const_iterator`
`reverse_iterator` | `const_reverse_iterator`
`const_reverse_iterator` | std::reverse_iterator <const_iterator>
`size_type` | std::size_t
`difference_type` | std::ptrdiff_t

Note: `iterator` and `const_iterator` are the same type because string views are views into constant character sequences.

### Member functions

(constructor) | constructs a `basic_string_view` (public member function)
operator= | assigns a view (public member function)

##### Iterators

begincbegin | returns an iterator to the beginning (public member function)
endcend | returns an iterator to the end (public member function)
rbegincrbegin | returns a reverse iterator to the beginning (public member function)
rendcrend | returns a reverse iterator to the end (public member function)

##### Element access

operator[] | access specified character (public member function)
at | access specified character with bounds checking (public member function)
front | accesses the first character (public member function)
back | accesses the last character (public member function)
data | returns a pointer to the first character of a view (public member function)

##### Capacity

sizelength | returns the number of characters (public member function)
max_size | returns the maximum number of characters (public member function)
empty | checks whether the view is empty (public member function)

##### Modifiers

remove_prefix | Shrinks the view by moving its start forward (public member function)
remove_suffix | Shrinks the view by moving its end backward (public member function)
swap | swaps the contents (public member function)

##### Operations

to_stringoperator basic_string | creates a string from the view (public member function)
copy | copies characters (public member function)
substr | returns a substring (public member function)
compare | compares two views (public member function)
find | find characters in the view (public member function)
rfind | find the last occurrence of a substring (public member function)
find_first_of | find first occurrence of characters (public member function)
find_last_of | find last occurrence of characters (public member function)
find_first_not_of | find first absence of characters (public member function)
find_last_not_of | find last absence of characters (public member function)

### Constants

npos [static] | special value. The exact meaning depends on the context (public static member constant)

### Non-member functions

operator==operator!=operator<operator>operator<=operator>= | lexicographically compares two views (function template)

##### Input/output

operator<< | performs stream output on views (function template)

### Helper classes

std::hash<std::experimental::string_view>std::hash<std::experimental::wstring_view>std::hash<std::experimental::u16string_view>std::hash<std::experimental::u32string_view> | hash support for views (class template specialization)

### Feature test macros

__cpp_lib_experimental_string_view | a value of at least 201411 indicates that basic_string_view template is supported (macro constant)

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