1*0fca6ea1SDimitry Andric //===----------------------------------------------------------------------===// 2*0fca6ea1SDimitry Andric // 3*0fca6ea1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*0fca6ea1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5*0fca6ea1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*0fca6ea1SDimitry Andric // 7*0fca6ea1SDimitry Andric //===----------------------------------------------------------------------===// 8*0fca6ea1SDimitry Andric 9*0fca6ea1SDimitry Andric #ifndef _LIBCPP___PSTL_DISPATCH_H 10*0fca6ea1SDimitry Andric #define _LIBCPP___PSTL_DISPATCH_H 11*0fca6ea1SDimitry Andric 12*0fca6ea1SDimitry Andric #include <__config> 13*0fca6ea1SDimitry Andric #include <__pstl/backend_fwd.h> 14*0fca6ea1SDimitry Andric #include <__type_traits/conditional.h> 15*0fca6ea1SDimitry Andric #include <__type_traits/enable_if.h> 16*0fca6ea1SDimitry Andric #include <__type_traits/integral_constant.h> 17*0fca6ea1SDimitry Andric #include <__type_traits/type_identity.h> 18*0fca6ea1SDimitry Andric 19*0fca6ea1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 20*0fca6ea1SDimitry Andric # pragma GCC system_header 21*0fca6ea1SDimitry Andric #endif 22*0fca6ea1SDimitry Andric 23*0fca6ea1SDimitry Andric _LIBCPP_PUSH_MACROS 24*0fca6ea1SDimitry Andric #include <__undef_macros> 25*0fca6ea1SDimitry Andric 26*0fca6ea1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 27*0fca6ea1SDimitry Andric namespace __pstl { 28*0fca6ea1SDimitry Andric 29*0fca6ea1SDimitry Andric template <template <class, class> class _Algorithm, class _Backend, class _ExecutionPolicy, class = void> 30*0fca6ea1SDimitry Andric constexpr bool __is_implemented_v = false; 31*0fca6ea1SDimitry Andric 32*0fca6ea1SDimitry Andric template <template <class, class> class _Algorithm, class _Backend, class _ExecutionPolicy> 33*0fca6ea1SDimitry Andric constexpr bool __is_implemented_v<_Algorithm, 34*0fca6ea1SDimitry Andric _Backend, 35*0fca6ea1SDimitry Andric _ExecutionPolicy, 36*0fca6ea1SDimitry Andric __enable_if_t<sizeof(_Algorithm<_Backend, _ExecutionPolicy>)>> = true; 37*0fca6ea1SDimitry Andric 38*0fca6ea1SDimitry Andric // Helpful to provide better error messages. This will show the algorithm and the execution policy 39*0fca6ea1SDimitry Andric // in the compiler diagnostic. 40*0fca6ea1SDimitry Andric template <template <class, class> class _Algorithm, class _ExecutionPolicy> 41*0fca6ea1SDimitry Andric constexpr bool __cant_find_backend_for = false; 42*0fca6ea1SDimitry Andric 43*0fca6ea1SDimitry Andric template <template <class, class> class _Algorithm, class _BackendConfiguration, class _ExecutionPolicy> 44*0fca6ea1SDimitry Andric struct __find_first_implemented; 45*0fca6ea1SDimitry Andric 46*0fca6ea1SDimitry Andric template <template <class, class> class _Algorithm, class _ExecutionPolicy> 47*0fca6ea1SDimitry Andric struct __find_first_implemented<_Algorithm, __backend_configuration<>, _ExecutionPolicy> { 48*0fca6ea1SDimitry Andric static_assert(__cant_find_backend_for<_Algorithm, _ExecutionPolicy>, 49*0fca6ea1SDimitry Andric "Could not find a PSTL backend for the given algorithm and execution policy"); 50*0fca6ea1SDimitry Andric }; 51*0fca6ea1SDimitry Andric 52*0fca6ea1SDimitry Andric template <template <class, class> class _Algorithm, class _B1, class... _Bn, class _ExecutionPolicy> 53*0fca6ea1SDimitry Andric struct __find_first_implemented<_Algorithm, __backend_configuration<_B1, _Bn...>, _ExecutionPolicy> 54*0fca6ea1SDimitry Andric : _If<__is_implemented_v<_Algorithm, _B1, _ExecutionPolicy>, 55*0fca6ea1SDimitry Andric __type_identity<_Algorithm<_B1, _ExecutionPolicy>>, 56*0fca6ea1SDimitry Andric __find_first_implemented<_Algorithm, __backend_configuration<_Bn...>, _ExecutionPolicy> > {}; 57*0fca6ea1SDimitry Andric 58*0fca6ea1SDimitry Andric template <template <class, class> class _Algorithm, class _BackendConfiguration, class _ExecutionPolicy> 59*0fca6ea1SDimitry Andric using __dispatch = typename __find_first_implemented<_Algorithm, _BackendConfiguration, _ExecutionPolicy>::type; 60*0fca6ea1SDimitry Andric 61*0fca6ea1SDimitry Andric } // namespace __pstl 62*0fca6ea1SDimitry Andric _LIBCPP_END_NAMESPACE_STD 63*0fca6ea1SDimitry Andric 64*0fca6ea1SDimitry Andric _LIBCPP_POP_MACROS 65*0fca6ea1SDimitry Andric 66*0fca6ea1SDimitry Andric #endif // _LIBCPP___PSTL_DISPATCH_H 67