21 Strings library [strings]

21.3 String classes [string.classes]

21.3.2 Header <string> synopsis [string.syn]

#include <compare> // see [compare.syn] #include <initializer_list> // see [initializer.list.syn] namespace std { // [char.traits], character traits template<class charT> struct char_traits; template<> struct char_traits<char>; template<> struct char_traits<char8_t>; template<> struct char_traits<char16_t>; template<> struct char_traits<char32_t>; template<> struct char_traits<wchar_t>; // [basic.string], basic_­string template<class charT, class traits = char_traits<charT>, class Allocator = allocator<charT>> class basic_string; template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const basic_string<charT, traits, Allocator>& lhs, const basic_string<charT, traits, Allocator>& rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(basic_string<charT, traits, Allocator>&& lhs, const basic_string<charT, traits, Allocator>& rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const basic_string<charT, traits, Allocator>& lhs, basic_string<charT, traits, Allocator>&& rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(basic_string<charT, traits, Allocator>&& lhs, basic_string<charT, traits, Allocator>&& rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const charT* lhs, basic_string<charT, traits, Allocator>&& rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(charT lhs, const basic_string<charT, traits, Allocator>& rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(charT lhs, basic_string<charT, traits, Allocator>&& rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(basic_string<charT, traits, Allocator>&& lhs, const charT* rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const basic_string<charT, traits, Allocator>& lhs, charT rhs); template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(basic_string<charT, traits, Allocator>&& lhs, charT rhs); template<class charT, class traits, class Allocator> constexpr bool operator==(const basic_string<charT, traits, Allocator>& lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept; template<class charT, class traits, class Allocator> constexpr bool operator==(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs); template<class charT, class traits, class Allocator> constexpr see below operator<=>(const basic_string<charT, traits, Allocator>& lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept; template<class charT, class traits, class Allocator> constexpr see below operator<=>(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs); // [string.special], swap template<class charT, class traits, class Allocator> constexpr void swap(basic_string<charT, traits, Allocator>& lhs, basic_string<charT, traits, Allocator>& rhs) noexcept(noexcept(lhs.swap(rhs))); // [string.io], inserters and extractors template<class charT, class traits, class Allocator> basic_istream<charT, traits>& operator>>(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str); template<class charT, class traits, class Allocator> basic_ostream<charT, traits>& operator<<(basic_ostream<charT, traits>& os, const basic_string<charT, traits, Allocator>& str); template<class charT, class traits, class Allocator> basic_istream<charT, traits>& getline(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str, charT delim); template<class charT, class traits, class Allocator> basic_istream<charT, traits>& getline(basic_istream<charT, traits>&& is, basic_string<charT, traits, Allocator>& str, charT delim); template<class charT, class traits, class Allocator> basic_istream<charT, traits>& getline(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str); template<class charT, class traits, class Allocator> basic_istream<charT, traits>& getline(basic_istream<charT, traits>&& is, basic_string<charT, traits, Allocator>& str); // [string.erasure], erasure template<class charT, class traits, class Allocator, class U> constexpr typename basic_string<charT, traits, Allocator>::size_type erase(basic_string<charT, traits, Allocator>& c, const U& value); template<class charT, class traits, class Allocator, class Predicate> constexpr typename basic_string<charT, traits, Allocator>::size_type erase_if(basic_string<charT, traits, Allocator>& c, Predicate pred); // basic_­string typedef-names using string = basic_string<char>; using u8string = basic_string<char8_t>; using u16string = basic_string<char16_t>; using u32string = basic_string<char32_t>; using wstring = basic_string<wchar_t>; // [string.conversions], numeric conversions int stoi(const string& str, size_t* idx = nullptr, int base = 10); long stol(const string& str, size_t* idx = nullptr, int base = 10); unsigned long stoul(const string& str, size_t* idx = nullptr, int base = 10); long long stoll(const string& str, size_t* idx = nullptr, int base = 10); unsigned long long stoull(const string& str, size_t* idx = nullptr, int base = 10); float stof(const string& str, size_t* idx = nullptr); double stod(const string& str, size_t* idx = nullptr); long double stold(const string& str, size_t* idx = nullptr); string to_string(int val); string to_string(unsigned val); string to_string(long val); string to_string(unsigned long val); string to_string(long long val); string to_string(unsigned long long val); string to_string(float val); string to_string(double val); string to_string(long double val); int stoi(const wstring& str, size_t* idx = nullptr, int base = 10); long stol(const wstring& str, size_t* idx = nullptr, int base = 10); unsigned long stoul(const wstring& str, size_t* idx = nullptr, int base = 10); long long stoll(const wstring& str, size_t* idx = nullptr, int base = 10); unsigned long long stoull(const wstring& str, size_t* idx = nullptr, int base = 10); float stof(const wstring& str, size_t* idx = nullptr); double stod(const wstring& str, size_t* idx = nullptr); long double stold(const wstring& str, size_t* idx = nullptr); wstring to_wstring(int val); wstring to_wstring(unsigned val); wstring to_wstring(long val); wstring to_wstring(unsigned long val); wstring to_wstring(long long val); wstring to_wstring(unsigned long long val); wstring to_wstring(float val); wstring to_wstring(double val); wstring to_wstring(long double val); namespace pmr { template<class charT, class traits = char_traits<charT>> using basic_string = std::basic_string<charT, traits, polymorphic_allocator<charT>>; using string = basic_string<char>; using u8string = basic_string<char8_t>; using u16string = basic_string<char16_t>; using u32string = basic_string<char32_t>; using wstring = basic_string<wchar_t>; } // [basic.string.hash], hash support template<class T> struct hash; template<> struct hash<string>; template<> struct hash<u8string>; template<> struct hash<u16string>; template<> struct hash<u32string>; template<> struct hash<wstring>; template<> struct hash<pmr::string>; template<> struct hash<pmr::u8string>; template<> struct hash<pmr::u16string>; template<> struct hash<pmr::u32string>; template<> struct hash<pmr::wstring>; inline namespace literals { inline namespace string_literals { // [basic.string.literals], suffix for basic_­string literals constexpr string operator""s(const char* str, size_t len); constexpr u8string operator""s(const char8_t* str, size_t len); constexpr u16string operator""s(const char16_t* str, size_t len); constexpr u32string operator""s(const char32_t* str, size_t len); constexpr wstring operator""s(const wchar_t* str, size_t len); } } }