C++11 coding style - default param, std algorithm, non-member function begin() and end()

gistfile1.cpp

#include <vector>
#include <algorithm>
#include <iostream>
#include <string>

using std::cout;
using std::endl;
using std::vector;
using std::string;

class Person
{
private:
	int _age;
	string _name;
public:
	//1. Prefer default parameters than overloading
	
	/*
	Person(int age, string name) : _age(age), _name(name){}

	Person(int age) : _age(age), _name(""){}

	Person(string name) : _age(1), _name(name){}
	*/
	
	Person(int age=1, string name="") : _age(age), _name(name){}

	/*
	
	void GetOld() {
		_age++;
	}

	void GetOld(int n){
		_age += n;
	}
	*/

	void GetOld(int n=1){
		_age += n;
	}
	
	//When you implement in separate cpp, then follow below practices

	//void Person::GetOld(int n/*=1*/)
	//{
	//	_age += n;
	//
	//}

};

int main(int argc, char* argv[])
{
	vector<int> vInt(20); //without size when it's initialized, it will be crashed
	int i = 0;

	//vInt must pre-determin its size before it called in begin() and to be filled in generate_n function
	// also, size of the container must be matched with the size used in generate_n function.

	//2. Prefer std::generate to fill in arbitary container as it's more expressive and readable
	std::generate_n(begin(vInt), 10, [&i](){
		return i++;
	});

	std::generate_n(begin(vInt)+10, 10, [&i](){
		return i++;
	});


	std::for_each(begin(vInt), end(vInt), [](int element){
		cout<<element<<endl;		
	});

	//3. Prefer use standard algorithm as it become more powerful with C++11's lambda expression
	//all_of
	bool areAllItemsLessThan10 = std::all_of(begin(vInt), end(vInt), [](int n){
		return (n < 10);
	});
	cout<<(areAllItemsLessThan10?"Less Than 10" : "Bigger than 10")<<endl;
	
	//any_of
	bool isAnyOf9 = std::any_of(begin(vInt), end(vInt), [](int n){
		return n==9;
	});
	cout<<(isAnyOf9?"There is 9":"There is no 9")<<endl;

	//none_of

	auto biggerThan10 = [](int n){
		return n > 10;
	};
	bool noneOfbiggerThan10 = std::none_of(begin(vInt), end(vInt), biggerThan10);
	cout<<(noneOfbiggerThan10?"There is none of bigger than 10":"There is one of bigger than 10")<<endl;
	
	//4. with the help of non-member function begin() and end() that introduced in C++11,
	//	we can get iterator of c-array either.

	int intArr[] = {0,1,2,3,4,5,6,7,8,9};

	std::for_each(std::begin(intArr), std::end(intArr), [](int n){
		cout<<n<<endl;
	});


	return 0;
}

/*

0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Bigger than 10
There is 9
There is one of bigger than 10
0
1
2
3
4
5
6
7
8
9
Press any key to continue . . .

*/