C/C++ check if one bit is set in, i.e. int variable
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 nth bit from the right end:
CHECK_BIT(temp, n - 1)In C++, you can use std::bitset.
Check if bit N (starting from 0) is set:
temp & (1 << N)There is no builtin function for this.
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);