59 lines
1.4 KiB
C++
59 lines
1.4 KiB
C++
/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
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#include "ns3/callback.h"
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#include "ns3/assert.h"
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#include <iostream>
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using namespace ns3;
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static double
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CbOne (double a, double b)
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{
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std::cout << "invoke cbOne a=" << a << ", b=" << b << std::endl;
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return a;
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}
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class MyCb {
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public:
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int CbTwo (double a) {
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std::cout << "invoke cbTwo a=" << a << std::endl;
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return -5;
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}
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};
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int main (int argc, char *argv[])
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{
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// return type: double
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// first arg type: double
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// second arg type: double
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Callback<double, double, double> one;
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// build callback instance which points to cbOne function
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one = MakeCallback (&CbOne);
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// this is not a null callback
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NS_ASSERT (!one.IsNull ());
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// invoke cbOne function through callback instance
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double retOne;
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retOne = one (10.0, 20.0);
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// return type: int
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// first arg type: double
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Callback<int, double> two;
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MyCb cb;
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// build callback instance which points to MyCb::cbTwo
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two = MakeCallback (&MyCb::CbTwo, &cb);
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// this is not a null callback
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NS_ASSERT (!two.IsNull ());
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// invoke MyCb::cbTwo through callback instance
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int retTwo;
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retTwo = two (10.0);
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two = MakeNullCallback<int, double> ();
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// invoking a null callback is just like
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// invoking a null function pointer:
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// it will crash.
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//int retTwoNull = two (20.0);
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NS_ASSERT (two.IsNull ());
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return 0;
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}
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