opm-simulators/opm/simulators/linalg/cuistl/detail/has_function.hpp
2023-05-31 15:03:31 +02:00

126 lines
4.0 KiB
C++

/*
Copyright 2022-2023 SINTEF AS
This file is part of the Open Porous Media project (OPM).
OPM is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OPM is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with OPM. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPM_CUISTL_DETAIL_HAS_FUNCTION_HPP
#define OPM_CUISTL_DETAIL_HAS_FUNCTION_HPP
#include <type_traits>
/**
* Simple utility structs to test for the existence of functions in types.
*
* Note that there are alternatives to this, see for instance
* https://stackoverflow.com/questions/257288/templated-check-for-the-existence-of-a-class-member-function , however,
* this is by far the cleanest approach for where this is going to be used for now.
*
* TODO: Use the requires-keyword once C++20 becomes availble (https://en.cppreference.com/w/cpp/language/constraints ).
* With C++20 this file can be removed.
*/
namespace Opm::cuistl::detail
{
/**
* @brief The has_should_call_pre class detects the presence of the method shouldCallPre
*
* Usage:
*
* @code{.cpp}
* if constexpr (has_should_call_pre<decltype(preconditioner)>::value) {
* // We know that the function shouldCallPre is present:
* auto shouldCallPre = preconditioner.shouldCallPre();
* }
* @endcode
*
* @note This is mainly done in the GPU preconditioner to avoid having to copy data in the pre step.
*/
template <typename T>
class has_should_call_pre
{
template <typename U>
static std::true_type test(decltype(&U::shouldCallPre));
template <typename U>
static std::false_type test(...);
public:
static constexpr bool value = std::is_same_v<decltype(test<T>(0)), std::true_type>;
};
/**
* @brief The has_should_call_post class detects the presence of the method shouldCallPost
*
* Usage:
*
* @code{.cpp}
* if constexpr (has_should_call_post<decltype(preconditioner)>::value) {
* // We know that the function shouldCallPost is present:
* auto shouldCallPost = preconditioner.shouldCallPost();
* }
* @endcode
*
* @note This is mainly done in the GPU preconditioner to avoid having to copy data in the post step.
*/
template <typename T>
class has_should_call_post
{
template <typename U>
static std::true_type test(decltype(&U::shouldCallPost));
template <typename U>
static std::false_type test(...);
public:
static constexpr bool value = std::is_same_v<decltype(test<T>(0)), std::true_type>;
};
/**
* @brief The has_communication class checks if the type has the member function getCommunication.
*
* This is used in the SolverAdapter to check if the operator has a communication, and it will then select a different
* path accordingly.
*/
template <typename T>
class has_communication
{
template <typename U>
static std::true_type test(decltype(&U::getCommunication));
template <typename U>
static std::false_type test(...);
public:
static constexpr bool value = std::is_same_v<decltype(test<T>(0)), std::true_type>;
};
/**
* @brief The is_a_well_operator class tries to guess if the operator is a well type operator
*
* @note This is mainly done in the solver adapter to detect incompatible runtime arguments. When the GPU linear solve
* paths supports wells, this class can be removed.
*/
template <typename T>
class is_a_well_operator
{
template <typename U>
static std::true_type test(decltype(&U::addWellPressureEquations));
template <typename U>
static std::false_type test(...);
public:
static constexpr bool value = std::is_same_v<decltype(test<T>(0)), std::true_type>;
};
} // namespace Opm::cuistl::detail
#endif