std::bitset<N>::to_string

 

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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 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_ltis_lteq (C++20)(C++20)(C++20)   is_neqis_gtis_gteq (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) to_chars_result (C++17) from_chars_result (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-1^th) 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::basic_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 <bitset>
#include <iostream>
 
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)