sysrap/tests/CastTest.cc

0001 #include "OPTICKS_LOG.hh"
0002
0003 struct Base
0004 {
0005    Base(int base_ )
0006       :
0007       base(base_)
0008    {
0009    }
0010
0011    virtual void dump(const char* msg) = 0 ;
0012    int base ;
0013
0014    static void Dump(Base* obj, const char* msg)
0015    {
0016        if(obj)
0017        {
0018            obj->dump(msg) ;
0019        }
0020        else
0021        {
0022            LOG(info) << " NULL " << msg ;
0023        }
0024    }
0025
0026 };
0027
0028 struct A : public Base
0029 {
0030
0031    A(int a0_)
0032       :
0033       Base(100),
0034       a0(a0_)
0035    {
0036    }
0037
0038    int a0 ;
0039
0040    void dump(const char* msg)
0041    {
0042        LOG(info)
0043           << msg
0044           << " Base.base " << base
0045           << " A.a0 " << a0
0046           ;
0047    }
0048
0049 };
0050
0051 struct B : public Base
0052 {
0053    B(int b0_)
0054       :
0055       Base(200),
0056       b0(b0_)
0057    {
0058    }
0059
0060    void dump(const char* msg)
0061    {
0062        LOG(info)
0063           << msg
0064           << " Base.base " << base
0065           << " B.b0 " << b0
0066           ;
0067    }
0068
0069    int b0 ;
0070 };
0071
0072
0073
0074 void test_cast()
0075 {
0076     Base* x = new A(42) ;
0077
0078
0079     A* a_dc = dynamic_cast<A*>(x) ;
0080     Base::Dump(a_dc, "a_dc");
0081
0082     A* a_rc = reinterpret_cast<A*>(x) ;
0083     Base::Dump(a_rc, "a_rc");
0084
0085     A* a_sc = static_cast<A*>(x) ;
0086     Base::Dump(a_sc, "a_sc");
0087
0088
0089
0090     B* b_dc = dynamic_cast<B*>(x) ;    // <--- only this one notices are casting to the wrong type and gives NULL
0091     Base::Dump(b_dc, "b_dc");
0092
0093     B* b_rc = reinterpret_cast<B*>(x) ;
0094     Base::Dump(b_rc, "b_rc");
0095
0096     B* b_sc = static_cast<B*>(x) ;
0097     Base::Dump(b_sc, "b_sc");
0098 }
0099
0100
0101
0102 void test_cast_2()
0103 {
0104      int a,b,c,d;
0105      char h = 1;
0106      short s = 1;
0107      void* p = nullptr;
0108      int i = 1;
0109
0110      assert( sizeof(long) == 8 );
0111
0112      std::cout << "a is at: " << reinterpret_cast<long>(&a) << std::endl;
0113      std::cout << "b is at: " << reinterpret_cast<long>(&b) << std::endl;
0114      std::cout << "c is at: " << reinterpret_cast<long>(&c) << std::endl;
0115      std::cout << "d is at: " << reinterpret_cast<long>(&d) << std::endl;
0116      std::cout << "Char is at: " << reinterpret_cast<long>(&h) << std::endl;
0117      std::cout << "Short is at: " << reinterpret_cast<long>(&s) << std::endl;
0118      std::cout << "Pointer is at: " << reinterpret_cast<long>(p) << std::endl;
0119      std::cout << "Int is at: " << reinterpret_cast<long>(&i) << std::endl;
0120 }
0121
0122
0123 int main(int argc, char** argv)
0124 {
0125     OPTICKS_LOG(argc, argv);
0126
0127     //test_cast();
0128
0129     test_cast_2();
0130
0131     return 0 ;
0132 }
0133
0134 //om- ; TEST=CastTest om-t
0135
0136