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7787 :: How to create generic type without C++ Template

• Clonk (orginal) [2021-04-13T09:32:26+02:00] view original

  Hello,

  Is it possible to define such a type that :

  type
    RawA {.importcpp: "A".} = object
    A[T] = distinct RawA
  Run

  The issue with this is that the type A will generate C++ templated code :A::A<T> and that will not compile since A (in C++) is not templated.

  Is it possible to have a generic Nim type that does not generate a C++ template code ?

  I've also thought of using an aggregation pattern :

  type
    A[T] := object
      raw : RawA
  Run

  But it complexify things and I would like to avoid it if possible.

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• PMunch (orginal) [2021-04-13T09:34:36+02:00] view original

  What is the end goal? Like what is your generic type supposed to hold and how it is supposed to interact with C++?

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• Clonk (orginal) [2021-04-13T09:41:21+02:00] view original

  For context, this happens during wrapping Tensor type of Torch library.

  torch::tensor type is not templated but the Tensor holds scalars of a given type.

  Therefore there is a non generic type RawTensor {.importcpp: "Tensor".} that map directly.

  The goal is to create a more idiomatic Nim API with a generic type Tensor that can be converted to RawTensor.

  The idea was to do Tensor[T] = distinct RawTensor `` but this generate C++ code ``torch::tensor<T>.

  hence, the question if it's possible to achieve such a thing

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