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#include <iostream>
using namespace std;
template<typename T1, typename T2>
class Promotion;
template<bool C, typename Ta, typename Tb>
class IfThenElse;
template<typename Ta, typename Tb>
class IfThenElse<true, Ta, Tb>
{
public :
typedef Ta ResultT;
};
template<typename Ta, typename Tb>
class IfThenElse<false, Ta, Tb>
{
public :
typedef Tb ResultT;
};
// #define ORIG
#ifdef ORIG
template<typename T1, typename T2>
class Promotion
{
public :
typedef typename IfThenElse< (sizeof(T1) > sizeof(T2)),
T1,
typename IfThenElse<(sizeof(T1) < sizeof(T2)),
T2,
void>::ResultT>::ResultT ResultT;
};
#else
template<typename T1, typename T2>
class Promotion
{
public :
typedef typename IfThenElse< (sizeof(T1) > sizeof(T2)), T1, T2>::ResultT ResultT;
};
#endif
struct Foo {
Foo() : d(987.65) { }
double d;
};
struct Bar : public Foo {
Bar() : c('x') { }
char c;
};
main()
{
Promotion< Foo, Bar >::ResultT x;
cout << sizeof( Foo ) << endl;
cout << sizeof( Bar ) << endl;
cout << sizeof( x ) << endl;
cout << sizeof( x.c ) << endl;
cout << sizeof( x.d ) << endl;
}
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