函数类function object

struct absInt
{
 int operator() (int val)
 {
 return val < 0 ? -val : val;
 }
};

 class Funclass
 {
 public:
  Funclass(){};
  bool operator()(CStr& mcstr)
  {
   
   std::cout<<mcstr.getStr()<<endl;
   return true;
  }
 };

 

 

int i = -42;
absInt absObj;  // object that defines function call operator
unsigned int ui = absObj(i);     // calls absInt::operator(int)

 class GT_cls {
     public:
         GT_cls(size_t val = 0): bound(val) { }
         bool operator()(const string &s)
                            { return s.size() >= bound; }
     private:
         std::string::size_type bound;
     };