auto and lambda

The C++ 11 standards are starting to take more and more cue’s from other languages where you are able to create functions on the fly (lambda). With also adding the “auto” keyword which will allow the program to automatically figure out what type of variable will be returned from lambda function.

So here the break up of the lambda function is

<return type> <[optional local variables to be used]>(optional parameters);

The optional local variables are abit like the “use” within PHP (use)

So the full code is

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(int argc, char* argv[])
	int num = 30;
	int anothernum = 0;
	auto func = [&anothernum](int i) {
			cout << "Parameter passed in :" << i << "\n";
			anothernum = anothernum + 10; // alter the value passed in.
			return 50;	// return a value and use the auto keyword.
	int ret = func(num);
	cout << "Return from func :" << ret << "\n";
	cout << "Another num :" << anothernum << "\n";
	return 0;

and the output would be

Parameter passed in : 30
Return from func : 50
Another num : 10;

To compile with g++ I used these parameters

g++ <filename> -o <outfilename> -std=c++11