C/C++ check if one bit is set in, i.e. int variable

Check if bit N (starting from 0) is set:

temp & (1 << N)

There is no builtin function for this.

In C, if you want to hide bit manipulation, you can write a macro:

#define CHECK_BIT(var,pos) ((var) & (1<<(pos)))

and use it this way to check the n^th bit from the right end:

CHECK_BIT(temp, n - 1)

In C++, you can use std::bitset.

I would just use a std::bitset if it's C++. Simple. Straight-forward. No chance for stupid errors.

typedef std::bitset<sizeof(int)> IntBits;
bool is_set = IntBits(value).test(position);

or how about this silliness

template<unsigned int Exp>
struct pow_2 {
    static const unsigned int value = 2 * pow_2<Exp-1>::value;
};

template<>
struct pow_2<0> {
    static const unsigned int value = 1;
};

template<unsigned int Pos>
bool is_bit_set(unsigned int value)
{
    return (value & pow_2<Pos>::value) != 0;
} 

bool result = is_bit_set<2>(value);