🚀 go-pugleaf

Subject: mutable can be removed...
Newsgroups: comp.std.c++
Organization: Fysisk institutt, Universitetet i Bergen
Summary: mutable semantic can be realized by template function.
Keywords: C++, mutable

Consider the following:

template<class T> T* remove_constness_from(const T* p)
{
   return const_cast<T*>(p);
}

So now instead of:

struct X { 
   mutable int i; 
   void set(int i_) const; 
};
void X::set(int i_) const { 
   i = i_; 
} 

one can wright:

struct X { 
   int i; 
   void set(int i_) const;
};
void X::set(int i_) const {
   remove_constness_from(this)->i = i_; 
} 
 
And remove_constness_from is more useful than mutable because in this 
case to make any class member looks like mutable one don't even need to 
modify class definition! And of cause lines like 
"remove_constness_from(this)->i = i_;"
will show explicitly what somebody does...

>From this point of view mutable keyword can be removed from C++. And it 
will not break any real code because as I now there is no compiler that 
can compile such code!
And of cause this will make C++ standard shorter...

--
Regards, Igor Boukanov. 
mailto:igor.boukanov@fi.uib.no  
http://www.fi.uib.no/~boukanov/
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