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  1. #include <functional>
  2. #include <iostream>
  3. #include <vector>
  4.  
  5.  
  6.     class Test
  7.     {
  8.     public:
  9.           Test (int testType) : m_testType(testType) {};
  10.           void blah() { std::cout << "BLAH! " << m_testType << std::endl; }
  11.           void blahWithParmeter(std::string p) { std::cout << "BLAH1! Parameter=" << p << std::endl; }
  12.           void blahWithParmeter2(std::string p) { std::cout << "BLAH2! Parameter=" << p << std::endl; }
  13.  
  14.           private:
  15.              int m_testType;
  16.  
  17.     };
  18.  
  19.     class Bim
  20.     {
  21.     public:
  22.           void operator()(){ std::cout << "BIM!" << std::endl; }
  23.     };
  24.  
  25.     void boum() { std::cout << "BOUM!" << std::endl; }
  26.  
  27.  
  28. int main()
  29. {
  30.     // store the member function of an object:
  31.     Test test(7);  
  32.     //std::function< void() > callback = std::bind( &Test::blah, test );
  33.     std::function< void() > callback = std::bind( &Test::blah, test );
  34.     callback();
  35.  
  36.     // store a callable object (by copy)
  37.     callback = Bim{};
  38.     callback();
  39.  
  40.     // store the address of a static funtion
  41.     callback = &boum;
  42.     callback();
  43.  
  44.     // store a copy of a lambda (that is a callable object)
  45.     callback = [&]{ test.blah(); }; // might be clearer than calling std::bind()
  46.     callback();
  47.  
  48.     // example of callback with parameter using a vector
  49.     typedef std::function<void(std::string&)> TstringCallback;
  50.  
  51.     std::vector <TstringCallback> callbackListStringParms;
  52.     callbackListStringParms.push_back( [&] (const std::string& tag) { test.blahWithParmeter(tag); }); 
  53.     callbackListStringParms.push_back( [&] (const std::string& tag) { test.blahWithParmeter2(tag); }); 
  54.  
  55.     std::string parm1 = "parm1";
  56.     std::string parm2 = "parm2";
  57.     int i = 0;
  58.     for (auto cb : callbackListStringParms ) 
  59.     {
  60.         ++i;
  61.         if (i == 1)
  62.             cb(parm1);
  63.         else
  64.             cb(parm2);
  65.  
  66.         }
  67. }
Success #stdin #stdout 0s 2992KB
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stdin
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Standard input is empty
stdout
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BLAH! 7
BIM!
BOUM!
BLAH! 7
BLAH1! Parameter=parm1
BLAH2! Parameter=parm2
https://ideone.com/tcBCeO
Derived from http://stackoverflow.com/questions/12338695/c11-styled-callbacks
language:
C++14 (gcc 8.3)
created:
12 years ago
visibility:
public

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