How do you exit from a void function in C++?

How can you prematurely exit from a function without returning a value if it is a void function? I have a void method that needs to not execute its code if a certain condition is true. I really don't want to have to change the method to actually return a value.

Use a return statement!

return;

or

if (condition) return;

You don't need to (and can't) specify any values, if your method returns void.

You mean like this?

void foo ( int i ) {
    if ( i < 0 ) return; // do nothing
    // do something
}

void foo() {
  /* do some stuff */
  if (!condition) {
    return;
  }
}

You can just use the return keyword just like you would in any other function.