std::bitset<N>::to_string

 

C++

Compiler support

Freestanding and hosted

Language

Standard library

Standard library headers

Named requirements

Feature test macros (C++20)

Language support library

Concepts library (C++20)

Metaprogramming library (C++11)

Diagnostics library

General utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms library

Numerics library

Localizations library

Input/output library

Filesystem library (C++17)

Regular expressions library (C++11)

Concurrency support library (C++11)

Technical specifications

Symbols index

External libraries

 

Utilities library

Language support Type support (basic types, RTTI) Library feature-test macros (C++20) Dynamic memory management Program utilities Coroutine support (C++20) Variadic functions is_constant_evaluated (C++20) is_within_lifetime (C++26) initializer_list (C++11) source_location (C++20) Three-way comparison (C++20) three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20)    is_eqis_neqis_ltis_lteqis_gtis_gteq (C++20)(C++20)(C++20)(C++20)(C++20)(C++20)

General utilities Date and time Function objects Formatting library (C++20) bitset hash (C++11) Relational operators (deprecated in C++20) rel_ops::operator!=rel_ops::operator> rel_ops::operator<=rel_ops::operator>= Integer comparison functions cmp_equalcmp_lesscmp_less_than (C++20)(C++20)(C++20)    cmp_not_equalcmp_greatercmp_greater_than (C++20)(C++20)(C++20) in_range (C++20) Swap and type operations swap ranges::swap (C++20) exchange (C++14) declval (C++11) to_underlying (C++23) forward (C++11) forward_like (C++23) move (C++11) move_if_noexcept (C++11) as_const (C++17) Common vocabulary types pair tuple (C++11) optional (C++17) any (C++17) variant (C++17) tuple_size (C++11) tuple_element (C++11) apply (C++17) make_from_tuple (C++17) expected (C++23) Elementary string conversions to_chars (C++17) from_chars (C++17) chars_format (C++17)

 

std::bitset

Member types

bitset::reference

Member functions

bitset::bitset

bitset::operator==bitset::operator!= (until C++20)

Element access

bitset::operator[]

bitset::test

bitset::allbitset::anybitset::none (C++11)

bitset::count

Capacity

bitset::size

Modifiers

bitset::operator&=bitset::operator|=bitset::operator^=bitset::operator~

bitset::operator<<=bitset::operator>>=bitset::operator<<bitset::operator>>

bitset::set

bitset::reset

bitset::flip

Conversions

bitset::to_string

bitset::to_ulong

bitset::to_ullong (C++11)

Non-member functions

operator&operator|operator^

operator<<operator>>

Helper classes

std::hash (C++11)

 

	(1)
template<     class CharT,     class Traits,     class Allocator > std::basic_string<CharT, Traits, Allocator>     to_string( CharT zero = CharT('0'), CharT one = CharT('1') ) const;			(until C++11)
template<     class CharT = char,     class Traits = std::char_traits<CharT>,     class Allocator = std::allocator<CharT> > std::basic_string<CharT, Traits, Allocator>     to_string( CharT zero = CharT('0'), CharT one = CharT('1') ) const;			(since C++11) (constexpr since C++23)
template< class CharT, class Traits > std::basic_string<CharT, Traits>     to_string( CharT zero = CharT('0'), CharT one = CharT('1') ) const;		(2)	(until C++11)
template< class CharT > std::basic_string<CharT>     to_string( CharT zero = CharT('0'), CharT one = CharT('1') ) const;		(3)	(until C++11)
std::string to_string( char zero = '0', char one = '1' ) const;		(4)	(until C++11)

Converts the contents of the bitset to a string. Uses zero to represent bits with value of false and one to represent bits with value of true.

The resulting string contains N characters with the first character corresponds to the last (N-1th) bit and the last character corresponding to the first bit.

All template type arguments need to be provided because function templates cannot have default template arguments. Overloads (2-4) are provided to simplify the invocations of to_string: 2) Uses the default allocator std::allocator. 3) Uses the default character trait std::char_traits and the default allocator std::allocator. 4) Uses the default character type char, the default character trait std::char_traits and the default allocator std::allocator.

(until C++11)

Parameters

zero	-	character to use to represent false
one	-	character to use to represent true

Return value

1) The converted string.

2) to_string<CharT, Traits, std::allocator<CharT>>(zero, one).

3) to_string<CharT, std::char_traits<CharT>, std::allocator<CharT>>(zero, one).

4) to_string<char, std::char_traits<char>, std::allocator<char>>(zero, one).

Exceptions

May throw std::bad_alloc from the std::string constructor.

Notes

Since C++11, functions templates can have default template arguments. LWG issue 1113 removed the helper overloads (2-4) and added the corresponding default template arguments in (1).

Example

Run this code

#include <iostream>
#include <bitset>
 
int main()
{
    std::bitset<8> b{42};
    std::cout << b.to_string() << '\n'
              << b.to_string('*') << '\n'
              << b.to_string('O', 'X') << '\n';
}

Output:

00101010
**1*1*1*
OOXOXOXO

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR	Applied to	Behavior as published	Correct behavior
LWG 396	C++98	zero and one bits were converted to characters ​0​ and 1 (which do not correspond to '0' and '1')	added parameters to provide values for these characters
LWG 434	C++98	all template arguments needed to be provided	added overloads (2-4)
LWG 853	C++98	overloads (2-4) did not have the default arguments added by LWG issue 396	also added

See also

to_ulong	returns an unsigned long integer representation of the data (public member function)
to_ullong (C++11)	returns an unsigned long long integer representation of the data (public member function)