21 Strings library [strings]

21.4 String view classes [string.view]

21.4.2 Header <string_­view> synopsis [string.view.synop]

#include <compare> // see [compare.syn] namespace std { // [string.view.template], class template basic_­string_­view template<class charT, class traits = char_traits<charT>> class basic_string_view; template<class charT, class traits> inline constexpr bool ranges::enable_view<basic_string_view<charT, traits>> = true; template<class charT, class traits> inline constexpr bool ranges::enable_borrowed_range<basic_string_view<charT, traits>> = true; // [string.view.comparison], non-member comparison functions template<class charT, class traits> constexpr bool operator==(basic_string_view<charT, traits> x, basic_string_view<charT, traits> y) noexcept; template<class charT, class traits> constexpr see below operator<=>(basic_string_view<charT, traits> x, basic_string_view<charT, traits> y) noexcept; // see [string.view.comparison], sufficient additional overloads of comparison functions // [string.view.io], inserters and extractors template<class charT, class traits> basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os, basic_string_view<charT, traits> str); // basic_­string_­view typedef-names using string_view = basic_string_view<char>; using u8string_view = basic_string_view<char8_t>; using u16string_view = basic_string_view<char16_t>; using u32string_view = basic_string_view<char32_t>; using wstring_view = basic_string_view<wchar_t>; // [string.view.hash], hash support template<class T> struct hash; template<> struct hash<string_view>; template<> struct hash<u8string_view>; template<> struct hash<u16string_view>; template<> struct hash<u32string_view>; template<> struct hash<wstring_view>; inline namespace literals { inline namespace string_view_literals { // [string.view.literals], suffix for basic_­string_­view literals constexpr string_view operator""sv(const char* str, size_t len) noexcept; constexpr u8string_view operator""sv(const char8_t* str, size_t len) noexcept; constexpr u16string_view operator""sv(const char16_t* str, size_t len) noexcept; constexpr u32string_view operator""sv(const char32_t* str, size_t len) noexcept; constexpr wstring_view operator""sv(const wchar_t* str, size_t len) noexcept; } } }
The function templates defined in [utility.swap] and [iterator.range] are available when <string_­view> is included.