static mutable member variables in C++?

c++ static member mutable
shuhalo picture shuhalo · Oct 17, 2010 · Viewed 7.7k times · Source

why or for what reason is it not possible to declare a class member variable in C++ as static mutable? Something like

static mutable int t; //This won't compile

For me, there is no reason to ban such declarations. E.g. for reasons like maintaining a global class-wide statistics, it may be convenient to have static variable that can be altered by (logically) const methods. So either this is sort of a misdesign in C++ and unnecessarily complicated, or there is a practical or theoretical reason which I cannot see.

Answer

AnT picture AnT · Oct 17, 2010

Non-const static members of the class can already be modified by any (const and non-const) methods of the class. There's no need and no point in declaring it with mutable. That would achieve absolutely nothing.

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