Compiler Error C3673

  • Article

'type' : class does not have a copy-constructor

A user-defined constructor is needed to copy objects of CLR ref types. For more information, see C++ Stack Semantics for Reference Types.

Example

The following sample generates C3673.

// C3673.cpp
// compile with: /clr
public ref struct R {
public:
   R() {}
   // Uncomment the following line to resolve.
   // R(R% p) {}
};

int main() {
   R r;
   R s = r;   // C3673
}

The following sample generates C3673.

// C3673_b.cpp
// compile with: /clr /c
// C3673 expected
using namespace System;
[AttributeUsage(AttributeTargets::Class)]
ref class MyAttr : public Attribute {
public:
   MyAttr() {}
   // Uncomment the following line to resolve.
   // MyAttr(int i) {}
   property int Priority;
   property int Version;
};

[MyAttr] 
ref class ClassA {};   // OK, no arguments

[MyAttr(Priority = 1)] 
ref class ClassB {};   // OK, named argument

[MyAttr(123)]
ref class ClassC {};   // Positional argument

[MyAttr(123, Version = 1)]
ref class ClassD {};   // Positional and named