#include <iostream>
#include <string>
using namespace std;
 
double eval(string const&) {
   return 1.0;
}

int main() {
    using Test = pair<string, double>;
    using Tests = Test[];
    const Tests tests {
        { "1 1 +", 2.0 },
        { "1 1 -", 0.0 },
        { "1 1 *", 1.0 },
        { "1 1 /", 1.0 }
    };
    for (auto test: tests) {
        const auto result = eval(test.first);
        cout << '\"' << test.first << "\" == " << result << 
            (test.second == result ? " [pass]" : " [fail]") << endl;
    }

    return 0;
}