differentiablefunction.hh

// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
 
// SPDX-FileCopyrightText: Copyright © DUNE Project contributors, see file AUTHORS.md
// SPDX-License-Identifier: LicenseRef-GPL-2.0-only-with-DUNE-exception OR LGPL-3.0-or-later
 
#ifndef DUNE_FUNCTIONS_COMMON_DIFFERENTIABLE_FUNCTION_HH
#define DUNE_FUNCTIONS_COMMON_DIFFERENTIABLE_FUNCTION_HH
 
#include <type_traits>
 
#include <dune/common/typeutilities.hh>
 
#include <dune/functions/common/type_traits.hh>
#include <dune/functions/common/defaultderivativetraits.hh>
#include <dune/functions/common/differentiablefunction_imp.hh>
#include <dune/functions/common/signature.hh>
#include <dune/functions/common/typeerasure.hh>
#include <dune/functions/common/functionconcepts.hh>
 
namespace Dune {
namespace Functions {
 
 
 
/*
 * Default implementation is empty
 * The actual implementation is only given if Signature is an type
 * describing a function signature as Range(Domain).
 */
template<class Signature, template<class> class DerivativeTraits=DefaultDerivativeTraits, size_t bufferSize=56>
class DifferentiableFunction
{};
 
 
 
namespace Imp
{
 
  template<class S, template<class> class DerivativeTraits, size_t bufferSize>
  struct DifferentiableFunctionTraits
  {
    using Signature = S;
 
    using Range = typename SignatureTraits<Signature>::Range;
 
    using Domain = typename SignatureTraits<Signature>::Domain;
 
    using DerivativeSignature = typename SignatureTraits<Signature>::template DerivativeSignature<DerivativeTraits>;
 
    using DerivativeInterface = DifferentiableFunction<DerivativeSignature, DerivativeTraits, bufferSize>;
 
    using Concept = DifferentiableFunctionWrapperInterface<Signature, DerivativeInterface>;
 
    template<class B>
    using Model = DifferentiableFunctionWrapperImplementation<Signature, DerivativeInterface, B>;
  };
}
 
 
 
template<class Range, class Domain, template<class> class DerivativeTraits, size_t bufferSize>
class DifferentiableFunction< Range(Domain), DerivativeTraits, bufferSize> :
  public TypeErasureBase<
    typename Imp::DifferentiableFunctionTraits<Range(Domain), DerivativeTraits, bufferSize>::Concept,
    Imp::DifferentiableFunctionTraits<Range(Domain), DerivativeTraits, bufferSize>::template Model>
{
  using Traits = Imp::DifferentiableFunctionTraits<Range(Domain), DerivativeTraits, bufferSize>;
 
  using Base = TypeErasureBase<typename Traits::Concept, Traits::template Model>;
 
  using DerivativeInterface = typename Traits::DerivativeInterface;
 
public:
 
  template<class F, disableCopyMove<DifferentiableFunction, F> = 0 >
  DifferentiableFunction(F&& f) :
    Base(std::forward<F>(f))
  {
    static_assert(Dune::Functions::Concept::isFunction<F, Range(Domain)>(), "Trying to construct a DifferentiableFunction from type that does not model the Function concept");
  }
 
  DifferentiableFunction() = default;
 
  Range operator() (const Domain& x) const
  {
    return this->asInterface().operator()(x);
  }
 
  friend DerivativeInterface derivative(const DifferentiableFunction& t)
  {
    return t.asInterface().derivative();
  }
};
 
 
 
}} // namespace Dune::Functions
 
 
 
#endif // DUNE_FUNCTIONS_COMMON_DIFFERENTIABLE_FUNCTION_HH