C++ Bitset Library - bitset() Function

Description

The C++ constructor std::bitset::bitset() constructs and initializes a bitset container from C++ string object.

Declaration

Following is the declaration for std::bitset::bitset() constructor form std::bitset header.

C++98

template<class charT, class traits, class Alloc>
explicit bitset (const basic_string<charT,traits,Alloc>& str,
                 typename basic_string<charT,traits,Alloc>::size_type pos = 0,
                 typename basic_string<charT,traits,Alloc>::size_type n =
                 basic_string<charT,traits,Alloc>::npos
                 );

C++11

template <class charT, class traits, class Alloc>
explicit bitset (const basic_string<charT,traits,Alloc>& str,
                 typename basic_string<charT,traits,Alloc>::size_type pos = 0,
                 typename basic_string<charT,traits,Alloc>::size_type n =
                 basic_string<charT,traits,Alloc>::npos,
                 charT zero = charT('0'), charT one = charT('1')
                 );

Parameters

• str − String used to initialize the bitset.

• pos − A starting offset of str.

• n − Number of characters from str.

Return value

Constructor never returns value.

Exceptions

If pos > str.size() then method throws out_of_range exception.

Example

The following example shows the usage of std::bitset::bitset() constructor.

#include <iostream>
#include <bitset>
#include <string>

using namespace std;

int main(void) {
   string s = "1100";
   bitset<4>b(s);

   cout << b << endl;

   return 0;
}

Let us compile and run the above program, this will produce the following result −

1100