NAME¶

std::bitset::to_string - std::bitset::to_string

Synopsis¶

template< class CharT, class Traits, class Allocator
>

std::basic_string<CharT, Traits, Allocator> (until C++11)
to_string( CharT zero = CharT('0'),

CharT one = CharT('1') ) const;
template<

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

std::basic_string<CharT, Traits> (2) (until C++11)
to_string( CharT zero = CharT('0'),

CharT one = CharT('1') ) const;
template< class CharT >

std::basic_string<CharT> to_string( CharT zero =
CharT('0'), (3) (until C++11)

CharT one =
CharT('1') ) const;
std::string to_string( char zero = '0', char one = (4) (until C++11)
'1' ) const;

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. (until C++11)
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.

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

See also¶

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