C++ Binary to Decimal

Question

So I know there is a way to convert Dec to binary using the bitset library but can you do the same for binary to decimal using the bitset library? or do you have to do it manually?

bitset<8> bin_x(number);

Answer 1

You can, but it should be a string.

std::bitset<8> bits("1111");
std::cout << bits.to_ulong() << std::endl;

You can convert your integer to string and then pass it to bitset c-tor.

Live example

Answer 2

Another easy way (without using bitset library) using stoi

// #include <string>
std::string str = "-10010110001";
int dec = std::stoi(bin, nullptr, 2); // dec = -1201