difference_type.pass.cpp [plain text]
#include <memory>
#include <type_traits>
struct A
{
typedef short element_type;
typedef char difference_type;
};
struct B
{
typedef short element_type;
};
template <class T>
struct C {};
template <class T>
struct D
{
typedef char difference_type;
};
int main()
{
static_assert((std::is_same<std::pointer_traits<A>::difference_type, char>::value), "");
static_assert((std::is_same<std::pointer_traits<B>::difference_type, std::ptrdiff_t>::value), "");
static_assert((std::is_same<std::pointer_traits<C<double> >::difference_type, std::ptrdiff_t>::value), "");
static_assert((std::is_same<std::pointer_traits<D<int> >::difference_type, char>::value), "");
}