In C++, what happens if two different functions declare the same static variable?

Question

void foo() {
    static int x;
}

void bar() {
    static int x;
}

int main() {
    foo();
    bar();
}

Answer 1

They each see only their own one. A variable cannot be "seen" from outside the scope that it's declared in.

If, on the other hand, you did this:

static int x;

void foo() {
    static int x;
}

int main() {
    foo();
}

then foo() only sees its local x; the global x has been "hidden" by it. But changes to one don't affect the value of the other.

Answer 2

The variables are distinct, each function has it's own scope. So although both variables last for the lifetime of the process, they do not interfere with each other.