# std::bitset<N>::to_string

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< cpp‎ | utility‎ | bitset

| (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::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)

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