c-resources/CPlusPlus20ForProgrammers-m.../examples/ch20/fig20_06/fig20_06.cpp

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// fig20_06.cpp
// Demonstrating downcasting and runtime type information (RTTI).
#include <fmt/format.h>
#include <iostream>
#include <typeinfo>
#include <vector>
#include "Employee.h"
#include "SalariedEmployee.h"
#include "CommissionEmployee.h"
int main() {
// create derived-class objects
SalariedEmployee salaried{"John Smith", 800.0};
CommissionEmployee commission{"Sue Jones", 10000.0, .06};
// create and initialize vector of base-class pointers
std::vector<Employee*> employees{&salaried, &commission};
// polymorphically process each element in vector employees
for (Employee* employeePtr : employees) {
std::cout << fmt::format("{}\n", employeePtr->toString());
// determine whether employeePtr points to a SalariedEmployee;
// if not, dynamic_cast returns nullptr which evaluates to false
if (auto ptr{dynamic_cast<SalariedEmployee*>(employeePtr)}) {
double oldBaseSalary = ptr->getSalary();
std::cout << fmt::format("old salary: ${:.2f}\n", oldBaseSalary);
ptr->setSalary(1.10 * oldBaseSalary);
std::cout << fmt::format(
"new salary with 10% increase is: ${:.2f}\n",
ptr->getSalary());
}
std::cout << fmt::format("earned ${:.2f}\n\n",
employeePtr->earnings());
}
// display each object<63>s type
for (const Employee* employeePtr : employees) {
std::cout << fmt::format("{}\n", typeid(*employeePtr).name());
}
}
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