I am trying to write a vector 'uvector' class which:
- Acts like std::vector on non-POD types
- On POD types doesn't initialize elements on creation (use malloc/free without c'tors/d'tors).
So, why the compiler errors? What is wrong?
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// alias of std::vector
using uvector = std::vector<
typename std::enable_if<!std::is_pod<T>::value, T>::type,
// completely new class
struct uvector<typename std::enable_if<std::is_pod<T>::value, T>::type>
typedef T value_type;
typedef T* iterator;
T *f = 0; //!< Pointer to first element of vector.
T *l = 0; //!< Pointer to last element of vector.
T *c = 0; //!< Pointer to the end of allocated memory block of vector.
First, you have a couple missing typenames (one for each dependent ::type).
Second, type alias won't work here, for several reasons, the most fundamental of which is that std::vector, like the rest of the standard library containers, cannot be specialized. If you want a custom container, make a custom container that holds a vector as a member where necessary.