Compiler Error C3894

'var' : l-value use of initonly static data member is only allowed in the class constructor of class 'class'

Remarks

Static initonly data members can only be used as l-values at their point of declaration, or in a static constructor.

Instance (non-static) initonly data members can only be used as l-values at their point of declaration, or in instance (non-static) constructors.

Example

The following example generates C3894:

// C3894.cpp
// compile with: /clr
ref struct Y1 {
   initonly static int data_var = 0;

public:
   // class constructor
   static Y1() {
      data_var = 99;   // OK
      System::Console::WriteLine("in static constructor");
   }

   // not the class constructor
   Y1(int i) {
      data_var = i;   // C3894
   }

   static void Test() {}

};

int main() {
   Y1::data_var = 88;   // C3894
   int i = Y1::data_var;
   Y1 ^ MyY1 = gcnew Y1(99);
   Y1::Test();
}