ням

// 1
struct crap
{
    int kek;
    void shit() {
        return kek;
    }
};

int main() {
    crap test;
    return 0;
}
$ clang++ main.cpp -> error: void function 'shit' should not return a value [-Wreturn-type]

// 2
template<typename T>
struct crap
{
    int kek;
    void shit() {
        return kek;
    }
};

int main() {
    crap<int> test;
    return 0;
}
$ clang++ main.cpp -> OK

// 3
template<typename T>
struct crap
{
    int kek;
    void shit() {
        return kek;
    }
};

int main() {
    crap<int> test;
    test.shit();
    return 0;
}
$ clang++ test.cpp
test.cpp:6:3: error: void function 'shit' should not return a value [-Wreturn-type]
                return kek;
                ^      ~~~
test.cpp:12:7: note: in instantiation of member function 'crap<int>::shit' requested here
        test.shit();
             ^
1 error generated.

//4
template<typename T>
struct crap
{
    void shit() {
        return 0;
    }
};

int main() {
    return 0;
}
$ clang++ test.cpp
test.cpp:5:9: error: void function 'shit' should not return a value [-Wreturn-type]
        return 0;
        ^      ~
1 error generated.