C++ command design pattern
#include <iostream>
#include <vector>
#include <functional>
class Recipes
{
public:
static void brewCoffee() { std::cout << "dripping Coffee through filter\n"; }
static void brewTea() { std::cout << "steeping Tea\n"; }
static int amountWaterMl(int ml) { return ml; }
};
class CaffeineBeverage
{
public:
CaffeineBeverage(std::function<int()> amountWaterMl, std::function<void()> brew)
: _amountWaterMl(amountWaterMl)
, _brew(brew)
{}
void prepare() {
boilWater(_amountWaterMl());
_brew();
pourInCup();
}
private:
void boilWater(int ml) { std::cout << "boiling " << ml << " water\n"; }
void pourInCup() { std::cout << "pour in cup\n"; }
std::function<int()> _amountWaterMl;
std::function<void()> _brew;
};
class CoffeeMachine
{
public:
typedef std::vector<std::function<void()>> OrderQ;
OrderQ orders;
CoffeeMachine()
: orders()
{}
void request(OrderQ::value_type order)
{
orders.push_back(order);
}
void start()
{
for(auto const& order : orders) { order(); }
orders.clear();
}
};
int main()
{
CoffeeMachine coffeeMachine;
CaffeineBeverage coffee(
[] { return Recipes::amountWaterMl(150); }, &Recipes::brewCoffee);
CaffeineBeverage tea(
[] { return Recipes::amountWaterMl(200); }, &Recipes::brewTea);
coffeeMachine.request([&]{ coffee.prepare(); });
coffeeMachine.request([&]{ tea.prepare(); });
coffeeMachine.start();
return 0;
}