select_type.h

 
#pragma once
 
#include <type_traits>
#include <fwd.h>
 
namespace System
{
 
namespace Details
{
 
struct ByteBool
{
    typedef uint8_t InternalType;
 
    InternalType m_val;
 
    ByteBool()
        : m_val(false) {}
 
    explicit ByteBool(bool b)
        : m_val(b) {}
 
    ByteBool& operator=(bool b)
    {
        m_val = b;
        return *this;
    }
 
    operator bool() const
    {
        return !!m_val;
    }
 
    bool operator==(ByteBool rhs) const { return !!m_val == !!rhs.m_val; }
    
    bool operator==(bool rhs) const { return !!m_val == rhs; }
 
    bool operator<(ByteBool rhs) const { return !!m_val < !!rhs.m_val; }
    
    bool operator<(bool rhs) const { return !!m_val < rhs; }
};
 
inline bool operator==(bool lhs, ByteBool rhs) { return rhs.operator==(lhs); }
 
inline bool operator!=(ByteBool lhs, ByteBool rhs) { return !lhs.operator==(rhs);  }
 
inline bool operator!=(ByteBool lhs, bool rhs) { return !lhs.operator==(rhs); }
 
inline bool operator!=(bool lhs, ByteBool rhs) { return !operator==(lhs, rhs);  }
 
inline bool operator<(bool lhs, ByteBool rhs) { return (lhs != rhs) && !(rhs < lhs); }
//TODO >, <=, >= operators
 
static_assert(sizeof(ByteBool) == 1, "Size of ByteBool must be 1");
static_assert(sizeof(ByteBool[17]) == 17, "Alignment of ByteBool must be 1");
static_assert(std::is_standard_layout<ByteBool>::value, "ByteBool must have Standard Layout");
 
template<typename T>
struct SelectType
{
    using type = T;
};
 
template<>
struct SelectType<bool>
{
    using type = Details::ByteBool;
};
 
} // namespace Details
} // namespace System