5.4.1. Bitmask

template<typename E>
class Bitmask

Generic bitmask for an enumerated type.

This class can be used as a companion bitmask of any enumerated type whose values have been constructed so that a single bit is set for each enum value. The enumerated values can be seen as the names of the bits in the bitmask.

Bitwise operations are defined between masks of the same type, between a mask and its companion enumeration, and between enumerated values.

enum my_enum
{
    RED    = 1 << 0,
    GREEN  = 1 << 1,
    BLUE   = 1 << 2
};

// Combine enumerated labels to create a mask
Bitmask<my_enum> yellow_mask = RED | GREEN;

// Combine a mask with a value to create a new mask
Bitmask<my_enum> white_mask = yellow_mask | BLUE;

// Flip all the bits in the mask
Bitmask<my_enum> black_mask = ~white_mask;

// Set a bit in the mask
black_mask.set(RED);

// Test if a bit is set in the mask
bool is_red = white_mask.is_set(RED);

Template Parameters

E – The enumerated type for which the bitmask is constructed