C++ Lambdas: capture list vs. parameter list

Question

According to the C++11 standard, lambda expressions may use variables in the enclosing scope, by means of the capture list, the parameter list or both.

So, let\'s look

Answer 1

For example using stl algorithms:

std::vector items;
int factor;
auto foundItem = std::find_if(items.begin(), items.end(), 
[&factor](int const& a) 
{ 
   return a * factor == 100; 
});

In this case you're called in the lambda for every item in the container and you return if the value multiplied by a captured factor is 100. The code doesn't make much sense, it's just to show you an example where capture and parameter lists matter.