Extending FredEmmott::bindline

You can add additional bindline components by extending FredEmmott::bindline_extension_api::bindable_t:

  • you must implement the bind_to() method
  • you may override the ordering_requirements_v static constant

For details, see the reference documentation for bindable_t.

Example 

namespace TestNS {
template <int N>
class int_front_binder_t : public ::FredEmmott::bindline_extension_api::bindable_t {
public:
  template<class TFn>
  [[nodiscard]]
  constexpr auto bind_to(TFn&& fn) const {
    return std::bind_front(fn, N);
  }
};
}

This class can then be used in a bindline:

auto bound = fn | int_front_binder_t<123> {};

If you want to offer an API that is consistent with the built-in functions, you can implement a factory function that optionally takes the wrapped invocable as its first argument:

// Support `fn | bind_int_front<123>()`
template<int N>
auto bind_int_front() {
  return int_front_binder_t<N> {};
}

// Support `bind_int_front<123>(fn)`
template<int N, class TFn>
auto bind_int_front(TFn&& fn) {
  return std::forward<TFn>(fn) | bind_int_front<N>();
}

If it is not possible to distinguish between the two intended usages via overloads, see: