C-style bit-manipulation

A bit can be cleared using the bitwise AND operator (&).

// Bit x will be cleared
number &= ~(1LL << x);

Using std::bitset

reset(x) or set(x,false) - clears the bit at position x.

std::bitset<5> num(std::string("01100"));
num.reset(2);     // num is now 01000
num.reset(0);     // num is still 01000
num.set(3,false); // num is now 00000