Well, the situation is even trickier:

   (a, b) = (10, 20)

is allowed code in C++ (not in C). The result is that 20 is assigned to b, and a is untouched.

Contrast this to:

    a, b = 10, 20

where (as above) 10 is assigned to b and a is left untouched, because it is parsed as:

    a, (b = 10), 20

and I hope you agree that the behavior is very confusing.

C++17 is capable of multiple variable declaration, which is a similar concept.

    #include <tuple>
    #include <iostream>
    
    std::tuple<int, int> divide(int dividend, int divisor) {
        return  {dividend / divisor, dividend % divisor};
    }
    
    int main() {
        using namespace std;
        auto [quotient, remainder] = divide(14, 3);
        cout << quotient << ',' << remainder << endl;
    }

Such misleading code should trigger an error.