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@nonathaj
Last active February 1, 2016 21:56
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C++ Enum Mask template class
#ifndef _ENUM_MASK
#define _ENUM_MASK
#include <cstddef>
#include <bitset>
//struct for ensuring an enum has a count element.
//this does NOT validate that the count element is the last element
template<class T>
struct has_enum_count {
typedef char yes;
typedef yes(&no)[2];
template<class U> static yes test(decltype(U::Count)*);
template<class U> static no test(...);
//SFINAE magic.
static bool const value = sizeof(test<T>(0)) == sizeof(yes);
};
template<typename EnumType>
class EnumMask
{
static_assert(std::is_enum<EnumType>::value, "Type for EnumMask must be an Enum");
static_assert(has_enum_count<EnumType>::value, "Enum provided to EnumMask must have a \"Count\" option as the last element in the enum.");
public:
inline bool test(const EnumType i_key) const { return mask_.test(i_key); }
inline void set() { mask_.set(); }
inline void set(const EnumType i_key, bool i_val = true) { mask_.set(i_key, i_val); }
inline void reset() { mask_.reset(); }
inline void reset(const EnumType i_key) { mask_.reset(i_key); }
inline void flip() { mask_.flip(); }
inline void flip(const EnumType i_key) { mask_.flip(i_key); }
inline size_t count() const { return mask_.count(); } //number of set bits
inline size_t size() const { return mask_.size(); } //number of bits in the entire set
inline bool any() const { return mask_.any(); }
inline bool none() const { return mask_.none(); }
inline bool all() const { return mask_.all(); }
inline std::bitset<EnumType::Count> mask() const { return mask_; }
inline void mask(const std::bitset<EnumType::Count>& i_mask) { mask_ = i_mask; }
bool operator==(const EnumMask<EnumType>& i_other) const { return mask_ == i_other.mask_; }
bool operator!=(const EnumMask<EnumType>& i_other) const { return mask_ != i_other.mask_; }
EnumMask<EnumType> operator&=(const EnumMask<EnumType>& i_other)
{
mask_ &= i_other.mask_;
return *this;
}
EnumMask<EnumType> operator|=(const EnumMask<EnumType>& i_other)
{
mask_ |= i_other.mask_;
return *this;
}
EnumMask<EnumType> operator&(const EnumMask<EnumType>& i_other) const
{
EnumMask<EnumType> newMask;
newMask.mask_ = mask_ & i_other.mask_;
return newMask;
}
EnumMask<EnumType> operator|(const EnumMask<EnumType>& i_other) const
{
EnumMask<EnumType> newMask;
newMask.mask_ = mask_ | i_other.mask_;
return newMask;
}
EnumMask<EnumType> operator~() const
{
EnumMask<EnumType> newMask;
newMask.mask_ = ~mask_;
return newMask;
}
private:
std::bitset<EnumType::Count> mask_;
};
#endif //_ENUM_MASK
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