//test1.cpp
#include <iostream>
#include "test.hpp"

int main() {
    std::cout << foo<int>::bar.value << '\n';
    void f();
    f();
    std::cout << foo<int>::bar.value << '\n';
}

//test2.cpp
#include "test.hpp"

void f() {
    foo<int>::bar.value = 42;
}

// test.hpp
struct wrapped { int value; };

template <typename>
struct foo {
    static wrapped bar;
};
template <typename T> wrapped foo<T>::bar = { 0 };