osrm-backend/include/util/make_unique.hpp

47 lines
1.4 KiB
C++

#ifndef MAKE_UNIQUE_H_
#define MAKE_UNIQUE_H_
#include <cstdlib>
#include <memory>
#include <type_traits>
namespace osrm
{
// Implement make_unique according to N3656. Taken from libcxx's implementation
/// \brief Constructs a `new T()` with the given args and returns a
/// `unique_ptr<T>` which owns the object.
///
/// Example:
///
/// auto p = make_unique<int>();
/// auto p = make_unique<std::tuple<int, int>>(0, 1);
template <class T, class... Args>
typename std::enable_if<!std::is_array<T>::value, std::unique_ptr<T>>::type
make_unique(Args &&... args)
{
return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
}
/// \brief Constructs a `new T[n]` with the given args and returns a
/// `unique_ptr<T[]>` which owns the object.
///
/// \param n size of the new array.
///
/// Example:
///
/// auto p = make_unique<int[]>(2); // value-initializes the array with 0's.
template <class T>
typename std::enable_if<std::is_array<T>::value && std::extent<T>::value == 0,
std::unique_ptr<T>>::type
make_unique(size_t n)
{
return std::unique_ptr<T>(new typename std::remove_extent<T>::type[n]());
}
/// This function isn't used and is only here to provide better compile errors.
template <class T, class... Args>
typename std::enable_if<std::extent<T>::value != 0>::type make_unique(Args &&...) = delete;
}
#endif // MAKE_UNIQUE_H_