C++ cool tricks?

Question

Can anyone suggest me tricks in c++ like:
a=a+b-(b=a); //for swapping variables or:
(condition) ? true : false; //coditions, or:
string s = "abcde";
for (int x:s){ cout << x << endl; } //ranged for loop, or functions like:
stoi(string, nullptr, 10) //converts any base to base 10.

Answer 1

1) decltype() returns the type of a variable. Thus, you may use it when you do not have an idea about what the return type is going to be.

Eg - decltype(variable) var2;

2) typeid() accepts types and lets you compare them as if they were variables.

Eg - if(typeid(var2)==typeid(int)) cout<<"Int";

Answer 2

that's a lot of effort just to avoid semicolons ^^

Answer 3

auto variable = expression;
This means that the type is determined looking at the expression.