Re: Scoped enum question

From:
=?ISO-8859-1?Q?Marcel_M=FCller?= <news.5.maazl@spamgourmet.org>
Newsgroups:
comp.lang.c++
Date:
Mon, 10 Jun 2013 21:46:31 +0200
Message-ID:
<51b62d18$0$6627$9b4e6d93@newsspool2.arcor-online.net>
On 10.06.13 20.19, woodbrian77@gmail.com wrote:

uint8_t operator&(cmw_user_input_data_member_flags lhs,cmw_user_input_data_member_flags rhs)
{
   return static_cast<uint8_t>(lhs)& static_cast<uint8_t>(rhs);
}


Since the opposite conversion from uint8_t to enum class is also not
implicit, you might prefer
cmw_user_input_data_member_flags
operator&(cmw_user_input_data_member_flags
lhs,cmw_user_input_data_member_flags rhs)

Because I need this type of operators quite often I have a macro for
this purpose.

#define FLAGSENUM(T) \
inline static T operator|(T l, T r) \
{ return (T)((unsigned)l|(unsigned)r); } \
inline static T operator&(T l, T r) \
{ return (T)((unsigned)l&(unsigned)r); } \
inline static T& operator|=(T& l, T r) \
{ return l = (T)((unsigned)l|(unsigned)r); } \
inline static T& operator&=(T& l, T r) \
{ return l = (T)((unsigned)l&(unsigned)r); } \
inline static T operator*(bool l, T r) \
{ return (T)(-l&(unsigned)r); } \
inline static T operator*(T l, bool r) \
{ return (T)((unsigned)l&-r); } \
inline static T operator~(T a) \
{ return (T)~(unsigned)a; }

Well, I know, macros are evil, but AFAIK there is definitely no way
around without repeating myself over and over.

Marcel

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