C++ High Performance

Lambdas and std::function

As mentioned before, every lambda function has its own type, even if they have the same signature (and even if they are identical).

The signature of a std::function is defined as follows:

std::function< return_type ( parameter0, parameter1...) > 

So, a std::function returning nothing and having no parameters is defined like this...

auto func = std::function<void(void)>{}; 

A std::function returning a bool and having an int and a std::string as parameters is defined like this:

auto func = std::function<bool(int, std::string)>{};