/////////////////////////////////////////////////////////////////////

// TemplatesIntro.cpp - Demonstrate Template Syntax //

// //

// Jim Fawcett, CSE687 - Object Oriented Design, Spring 2017 //

/////////////////////////////////////////////////////////////////////

#include "Convert.h"

#include <string>

#include <iostream>

#include <functional>

/////////////////////////////////////////////////////////////////////

// Widget class - shows user defined types can be template arguments

class Widget

{

public:

Widget(const std::string& str = "") : state(str) {}

std::string& value() { return state; }

private:

std::string state;

};

std::ostream& operator<<(std::ostream& out, Widget& widget)

{

out << widget.value();

return out;

}

std::istream& operator >> (std::istream& in, Widget& widget)

{

std::string temp;

while (in.good()) // extract all the words from widget's string state

{

in >> temp;

widget.value() += temp + " ";

}

return in;

}

/////////////////////////////////////////////////////////////////////

// lambdas that provide mildly useful local processing

std::function<void()> putLine = []() { std::wcout << "\n"; };

std::function<void(size_t)> putLines = [](size_t n) {

for (size_t i = 0; i < n; ++i)

putLine();

};

std::function<void(const std::string&, char)> titleCore = [](const std::string& msg, char underline='-') {

std::cout << "\n " << msg.c_str();

std::wcout << "\n " << std::string(msg.size() + 2, underline).c_str();

};

std::function<void(const std::string&)> Title = [](const std::string& msg) { titleCore(msg, '='); };

std::function<void(const std::string&)> title = [](const std::string& msg) { titleCore(msg, '-'); };

/////////////////////////////////////////////////////////////////////

// Demo code

int main()

{

Title("Demonstrating Templates");

putLine();

title("Demonstrating Conversion of numerical types");

std::cout << "\n conversion of integer: " << Convert<int>::toString(42);

std::cout << "\n conversion of double: " << Convert<double>::toString(3.1415927);

putLine();

title("Demonstrating Conversion of Widget type");

Widget widget("Joe Widget");

std::string widgetStore = Convert<Widget>::toString(widget);

std::cout << "\n conversion of Widget: " << widgetStore;

Widget newWidget = Convert<Widget>::fromString(widgetStore);

std::cout << "\n newWidget state = " << newWidget.value();

putLines(2);

}