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Compiler Error C3744

__unhook must have at least 3 arguments for managed events

The __unhook function must take three parameters when used in a program that is compiled for Managed Extensions for C++.

__hook and __unhook are not compatible with /clr programming. Use the += and -= operators instead.

C3744 is only reachable using /clr:oldSyntax.

The following sample generates C3744:

// C3744.cpp
// compile with: /clr:oldSyntax
#using <mscorlib.dll>
using namespace System;

public __delegate void delegate1();

[ event_source(managed) ]
public __gc class CPSource {
   __event delegate1* event1;

public __gc class CReceiver {
   void Handler1() {

   void UnhookAll1(CPSource* pSrc, CReceiver* pRec) {
      __unhook(pSrc);   // C3744
      // The following line resolves the error.
      // __unhook(&CPSource::event1, pSrc, &CReceiver::Handler1);

int main() {