How to pass lambda to a lambda?

Question

I have not managed to find why this code does not work:

#include <iostream>
#include <functional>

using namespace std;

int main()
{
  auto xClosure = [](const function<void(int&)>& myFunction) {
    myFunction(10);};

  xClosure([]
       (int& number) -> void
       {cout<<number<<endl;
       });
  return 0;
}

It returns:

g++ test.cc -o test -std=c++14

 test.cc:9:5: error: no matching function for call to object of type 'const function<void
  (int &)>'

Answer 1

This has nothing to do with lambdas:

void test(const function<void(int&)>& myFunction) {
  myFunction(10);
}

this fails to compile for the same reason; you cannot bind the literal 10 to an int&.

Maybe you meant

const function<void(int)>& myFunction

doing so and also modifying the signature of your lambda should make your code compile.