Rules for using underscores in C++ identifier names

Hi everyone! I just started learning C++ and noticed that in some code examples people use underscores at the beginning of variable names, like `_value` or `__internal`. I understand this is probably some naming style, but it seems to me that the compiler behaves strangely with such names. For example, I tried writing this code: ```cpp #include class MyClass { private: int _value; public: MyClass(int v) : _value(v) {} int getValue() const { return _value; } }; int main() { MyClass obj(42); std::cout << obj.getValue() << std::endl; return 0; } ``` It compiled and worked fine, but then I tried doing this: ```cpp int _main() { return 0; } ``` And the compiler gave a warning. And when I tried to