Compiler Error C3217
Visual Studio 2015
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The latest version of this topic can be found at Compiler Error C3217.
param' : generic parameter cannot be constrained in this declaration
A constraint was ill formed; the constraint generic parameter must agree with the generic class template parameter.
The following sample generates C3217:
// C3217.cpp
// compile with: /clr
interface struct A {};
generic <class T>
ref class C {
generic <class T1>
where T : A // C3217
void f();
};
The following sample demonstrates a possible resolution:
// C3217b.cpp
// compile with: /clr /c
interface struct A {};
generic <class T>
ref class C {
generic <class T1>
where T1 : A
void f();
};
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