C++ using

using

using與C語言裡的typedef都是用來宣告別名的，那麼他們兩者有什麼差別呢？根據What is the difference between ‘typedef’ and ‘using’ in C++11?:

They(typedef and using) are largely the same, except that:
The alias declaration(using) is compatible with templates, whereas the C style typedef is not.

以下兩種寫法等價：

typedef int MyInt;

using MyInt = int;

至於在使用了template的情況下，則一定要用using，以下代碼來自TensorRT/samples/common/buffers.h：

using DeviceBuffer = GenericBuffer<DeviceAllocator, DeviceFree>;
using HostBuffer = GenericBuffer<HostAllocator, HostFree>;

參考連結

What is the difference between ‘typedef’ and ‘using’ in C++11?