ClickHouse/libs/libcommon/include/common/strong_typedef.h
2016-06-14 14:44:32 +03:00

42 lines
1.1 KiB
C++

#pragma once
#include <boost/operators.hpp>
/** https://svn.boost.org/trac/boost/ticket/5182
*/
template <class T>
struct StrongTypedef
: boost::totally_ordered1< StrongTypedef<T>
, boost::totally_ordered2< StrongTypedef<T>, T> >
{
using Self = StrongTypedef<T>;
T t;
explicit StrongTypedef(const T t_) : t(t_) {};
StrongTypedef(): t() {};
StrongTypedef(const Self & t_) : t(t_.t){}
Self & operator=(const Self & rhs) { t = rhs.t; return *this;}
Self & operator=(const T & rhs) { t = rhs; return *this;}
operator const T & () const {return t; }
operator T & () { return t; }
bool operator==(const Self & rhs) const { return t == rhs.t; }
bool operator<(const Self & rhs) const { return t < rhs.t; }
T & toUnderType() { return t; }
const T & toUnderType() const { return t; }
};
namespace std
{
template <class T>
struct hash<StrongTypedef<T>>
{
size_t operator()(const StrongTypedef<T> & x) const
{
return std::hash<T>()(x.toUnderType());
}
};
}
#define STRONG_TYPEDEF(T, D) using D = StrongTypedef<T>;