Using: bitset( string() )

[mathieu]

Hi there,

I must be doing something wrong, but I do not understand the
documentation for bitset( string ), shouldn't this be equivalent (ref
== mask ) ?


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

int main()
{
std::bitset<8> ref( 13ul );
std::cout << ref << std::endl;

const char v[] = "1101";
std::bitset<8> mask( std::string(v) );
std::cout << mask << std::endl;
return 0;
}


Thanks
-Mathieu

 

[mathieu]

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

int main()
{
std::bitset<8> ref( 13ul );
std::cout << ref << std::endl;

const char v[] = "1101";
std::bitset<8> mask( std::string(v) );
std::cout << mask << std::endl;
return 0;
}

You've stepped into a funky corner of C++ syntax. This code declares
mask to be a function, and the compiler converts its address to a bool
to insert it into a stream. Break up the definition of mask:

std::string str(v);
std::bitset<8> mask(str);

Thanks ! That was it.