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C++ convert operator

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Converting to Type works by overloading the Type() operator.

class MyClass {
public:
  operator Type() const {
    // return something of type Type
  }
};

For example, we could define a conversion of the MyVector to a bool to be false if the vector is empty and true otherwise.


  MyVector v;

  if (!v) {  // call bool()
    fmt::print("MyVector is empty\n");
  }

  v.add(42);
  if (v) {  // call bool()
    fmt::print("First value on MyVector is {}\n", v[0]);
  }

  v.add(21);
  v.add(7);
  v.add(3);

  string s = v;

  fmt::print("MyVector converted to string is '{}'\n", s);

Possible output

bool() returns false
MyVector is empty
bool() returns true
First value on MyVector is 42
MyVector converted to string is '42, 21, 7, 3'

References