Lambda Captures C++14

Question

I\'ve encountered a notation like:

int x = 4;
auto y = [&r = x, x = x+1]()->int { 
    r += 2;
    return x+2;
}();

Can you explain

Answer 1

This example is part of C++14 feature "Lambda capture Initializers", This allows creating lambda captures initialized with arbitrary expressions. Using this reference-captures can have different names than the referenced variable.

If you run your code :

int x = 4;
auto y = [&r = x, x = x+1]()->int { 
    r += 2; //r=6
    return x+2;//5+2
};
cout<