Why can't I define a function inside another function?

Question

This is not a lambda function question, I know that I can assign a lambda to a variable.

What\'s the point of allowing us to declare, but not define a function insid

Answer 1

Well, the answer is "historical reasons". In C you could have function declarations at block scope, and the C++ designers did not see the benefit in removing that option.

An example usage would be:

#include 

int main()
{
    int func();
    func();
}

int func()
{
    std::cout << "Hello\n";
}

IMO this is a bad idea because it is easy to make a mistake by providing a declaration that does not match the function's real definition, leading to undefined behaviour which will not be diagnosed by the compiler.