#include <utility>

template<template<typename T> class F, typename R, typename... Ts>
R dispatch(torch::Tensor input, Ts&& ... args) {
  switch(input.type().scalarType()) {
    case torch::ScalarType::Double:
      return F<double>()(input, std::forward<Ts>(args)...);
    case torch::ScalarType::Float:
      return F<float>()(input, std::forward<Ts>(args)...);
    case torch::ScalarType::Half:
      throw std::runtime_error("Half-precision float not supported");
    case torch::ScalarType::ComplexHalf:
      throw std::runtime_error("Half-precision complex float not supported");
    case torch::ScalarType::ComplexFloat:
      throw std::runtime_error("Complex float not supported");
    case torch::ScalarType::ComplexDouble:
      throw std::runtime_error("Complex double not supported");
    case torch::ScalarType::Long:
      return F<int64_t>()(input, std::forward<Ts>(args)...);
    case torch::ScalarType::Int:
      return F<int32_t>()(input, std::forward<Ts>(args)...);
    case torch::ScalarType::Short:
      return F<int16_t>()(input, std::forward<Ts>(args)...);
    case torch::ScalarType::Char:
      return F<int8_t>()(input, std::forward<Ts>(args)...);
    case torch::ScalarType::Byte:
      return F<uint8_t>()(input, std::forward<Ts>(args)...);
    case torch::ScalarType::Bool:
      return F<bool>()(input, std::forward<Ts>(args)...);
    case torch::ScalarType::QInt32:
      throw std::runtime_error("QInt32 not supported");
    //case torch::ScalarType::QInt16:
    //  throw std::runtime_error("QInt16 not supported");
    case torch::ScalarType::QInt8:
      throw std::runtime_error("QInt8 not supported");
    case torch::ScalarType::BFloat16:
      throw std::runtime_error("BFloat16 not supported");
    default:
      throw std::runtime_error("Unknown scalar type");
  }
}