Function returning a lambda expression
c++, c++11, function, lambda
Solution
You don't need a handcrafted function object, just use `std::function`, to which lambda functions are convertible:
This example returns the integer identity function:
std::function<int (int)> retFun() {
return [](int x) { return x; };
}
Problem
I wonder if it's possible to write a function that returns a lambda function in C++11. Of course one problem is how to declare such function. Each lambda has a type, but that type is not expressible in C++. I don't think this would work: ``` auto retFun() -> decltype ([](int x) -> int) { return [](int x) { return x; } } ``` Nor this: ``` int(int) retFun(); ``` I'm not aware of any automatic conversions from lambdas to, say, pointers to functions, or some such. Is the only solution handcrafting a function object and returning it?