// OK: g++-4.9 -Wall -g -O3 -o test test.cpp
// OK: clang++-3.4 -Wall -g -O3 -o test test.cpp

// OK  : clang++-3.5 -Wall -g -o test test.cpp
// FAIL: clang++-3.5 -Wall -g -O1 -o test test.cpp
/*
test.cpp:57:14: warning: reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true
      [-Wundefined-bool-conversion]
        if (&foo && foo.method())
             ^~~ ~~
1 warning generated.
*/

#include <iostream>
#include <cstdlib>

struct Foo{
        int *data;

        Foo();
        ~Foo();
        bool method() const;
};

Foo::Foo()
{
        const int len = 100;
        data = new int[len];
        for (int i=0; i<len; i++) data[i]=0;
        std::cout << "Foo constructor" << std::endl;
}

Foo::~Foo()
{
        delete[] data;
        std::cout << "Foo destructor" << std::endl;
}

bool Foo::method() const
{
        std::cout << "Foo::method(): foo object supposed to exist, really?" << std::endl
                  << "accessing foo::data[1]..." << std::endl;
        std::cout << "data[1]=" << data[1] << std::endl;
        return true;
}

const Foo&
nullFoo()
{
        Foo* nullFoo = NULL;
        return static_cast<const Foo&>(*nullFoo);
}

void
test(const Foo& foo)
{
        if (&foo && foo.method())
                std::cout << "foo exists and method() OK" << std::endl;
        else
                std::cout << "foo doesn't exist, OK" << std::endl;
}

int main(int argc, char* argv[])
{
        int useNullFoo = 1;

        if (argc == 2)
                useNullFoo = atoi(argv[1]);

        std::cout << "Usage: test [0/1]" << std::endl
                  << "       0 create object" << std::endl
                  << "       1 \"create\" null object (default)" << std::endl;

        if (useNullFoo)
                test(nullFoo());
        else
                test(Foo());

        return 0;
}