Error passing a lambda as default argument

The code below compiles fine, until I uncomment the line: lambda();. Why does it compile if I don't use the function relying on the default argument, but when I try to use the default argument, it doesn't compile anymore?

#include <iostream>    int main()  {         static auto lambdaDefaultParameter = []() // must be static, otherwise I get the error that a local variable can't be a default parameter      {          std::cout << "default\n";      };        // trying a lambda that takes another lambda as parameter      auto lambda = [](auto&& f = lambdaDefaultParameter)      {          f();      };        lambda([]() {std::cout << "test\n"; }); // ok      //lambda(); // error  }  

https://stackoverflow.com/questions/66773298/error-passing-a-lambda-as-default-argument March 24, 2021 at 08:54AM