std::basic_string

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C++ Standard Library
Language Utilities library Strings library Containers library Algorithms library Iterators library Numerics library Input/output library Localizations library Regular expressions library (C++11) Atomic operations library (C++11) Thread support library (C++11)
Strings library
Null-terminated strings Byte strings Multibyte strings Wide strings Classes basic_string char_traits
std::basic_string
Member functions basic_string::basic_string basic_string::operator= basic_string::assign basic_string::get_allocator Element access basic_string::at basic_string::operator[] basic_string::front (C++11) basic_string::back (C++11) basic_string::data basic_string::c_str Iterators basic_string::begin basic_string::cbegin (C++11) basic_string::end basic_string::cend (C++11) basic_string::rbegin basic_string::crbegin (C++11) basic_string::rend basic_string::crend (C++11) Capacity basic_string::empty basic_string::size basic_string::length basic_string::max_size basic_string::reserve basic_string::capacity basic_string::shrink_to_fit (C++11) Operations basic_string::clear basic_string::insert basic_string::erase basic_string::push_back basic_string::pop_back (C++11) basic_string::append basic_string::operator+= basic_string::compare basic_string::replace basic_string::substr basic_string::copy basic_string::resize basic_string::swap Search basic_string::find basic_string::rfind basic_string::find_first_of basic_string::find_first_not_of basic_string::find_last_of basic_string::find_last_not_of Constants basic_string::npos Non-member functions operator+ operator== operator!= operator< operator> operator<= operator>= swap(std::basic_string) operator<< operator>> getline stoi stol stoll (C++11) (C++11) (C++11) stoul stoull (C++11) (C++11) stof stod stold (C++11) (C++11) (C++11) to_string (C++11) to_wstring (C++11) Helper classes hash<std::string> hash<std::u16string> hash<std::u32string> hash<std::u16string> (C++11)

Defined in header <string>
template<     class CharT,     class Traits = std::char_traits<CharT>,     class Allocator = std::allocator<CharT> > class basic_string;

The class template basic_string stores and manipulates sequences of char-like objects (that is, objects for which a specialization of std::char_traits or compatible traits class is provided).

The elements of a basic_string are stored contiguously, that is, for a basic_string s, &*(s.begin() + n) == &*s.begin() + n for any n in [0, s.size()), or, equivalently, a pointer to s[0] can be passed to functions that expect a pointer to the first element of a charT[] array. (since C++11)

Several specializations for common character types are provided:

Defined in header <ostream>
Type	Definition
string	basic_string<char>
wstring	basic_string<wchar_t>
u16string	basic_string<char16_t>
u32string	basic_string<char32_t>

Contents 1 Member types 2 Member functions 2.1 Element access 2.2 Iterators 2.3 Capacity 2.4 Operations 2.5 Search 3 Constants 4 Non-member functions 4.1 Input/output 4.2 Numeric conversions 5 Helper classes

[edit] Member types

Member type	Definition
traits_type	Traits
value_type	Traits::char_type
allocator_type	Allocator
size_type	Unsigned integral type (usually size_t)
difference_type	Signed integer type (usually ptrdiff_t)
reference	Allocator::reference (until C++11) value_type& (since C++11)
const_reference	Allocator::const_reference (until C++11) const value_type& (since C++11)
pointer	T* (until C++11) std::allocator_traits<Allocator>::pointer (since C++11)
const_pointer	const T* (until C++11) std::allocator_traits<Allocator>::const_pointer (since C++11)
iterator	Random access iterator
const_iterator	Constant random access iterator
reverse_iterator	std::reverse_iterator<iterator>
const_reverse_iterator	std::reverse_iterator<const_iterator>

[edit] Member functions

(constructor)	constructs the basic_string (public member function)
operator=	assigns values to the string (public member function)
assign	assign characters to a string (public member function)
get_allocator	returns the associated allocator (public member function)
Element access
at	access specified character with bounds checking (public member function)
operator[]	access specified character (public member function)
front (C++11)	accesses the first character (public member function)
back (C++11)	accesses the last character (public member function)
data	returns a pointer to the first character of a string (public member function)
c_str	returns a non-modifiable standard C character array version of the string (public member function)
Iterators
begin cbegin (C++11)	returns an iterator to the beginning (public member function)
end cend (C++11)	returns an iterator to the end (public member function)
rbegin crbegin (C++11)	returns a reverse iterator to the beginning (public member function)
rend crend (C++11)	returns a reverse iterator to the end (public member function)
Capacity
empty	checks whether the string is empty (public member function)
size	returns the number of characters (public member function)
length	returns the length of the string (public member function)
max_size	returns the maximum number of characters (public member function)
reserve	reserves storage (public member function)
capacity	returns the number of characters that can be held in currently allocated storage (public member function)
shrink_to_fit (C++11)	reduces memory usage by freeing unused memory (public member function)
Operations
clear	clears the contents (public member function)
insert	inserts characters (public member function)
erase	removes characters (public member function)
push_back	inserts characters to the end (public member function)
pop_back (C++11)	removes the last character (public member function)
append	appends characters to the end (public member function)
operator+=	appends characters to the end (public member function)
compare	compares two strings (public member function)
replace	replaces every occurrence of specified characters (public member function)
substr	returns a substring (public member function)
copy	copies characters (public member function)
resize	changes the number of characters stored (public member function)
swap	swaps the contents (public member function)
Search
find	find characters in the string (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_first_not_of	find first absence of characters (public member function)
find_last_of	find last occurrence 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)

[edit] Non-member functions

operator+	concatenates two strings or a string and a char (function template)
operator== operator!= operator< operator> operator<= operator>=	lexicographically compares two strings (function template)
std::swap(std::basic_string)	specializes the std::swap algorithm (function template)
Input/output
operator<< operator>>	performs stream I/O of strings (function template)
getline	read data from an I/O stream into a string (function)
Numeric conversions
stoi stol stoll (C++11) (C++11) (C++11)	converts a string to an signed integer (function)
stoul stoull (C++11) (C++11)	converts a string to an unsigned integer (function)
stof stod stold (C++11) (C++11) (C++11)	converts a string to an floating point value (function)
to_string (C++11)	converts an integral or floating point value to string (function)
to_wstring (C++11)	converts an integral or floating point value to wstring (function)

[edit] Helper classes

std::hash<std::string> std::hash<std::u16string> std::hash<std::u32string> std::hash<std::wstring> (C++11) (C++11) (C++11) (C++11)	hash support for strings (class template specialization)