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/*
* GridTools
*
* Copyright (c) 2014-2019, ETH Zurich
* All rights reserved.
*
* Please, refer to the LICENSE file in the root directory.
* SPDX-License-Identifier: BSD-3-Clause
*/
#pragma once
namespace cpp_bindgen {
namespace for_each_detail {
template <class List>
struct for_each_impl;
template <template <class...> class L, class... Ts>
struct for_each_impl<L<Ts...>> {
template <class Fun>
static void exec(Fun const &fun) {
(void)(int[]){((void)fun(Ts{}), 0)...};
}
};
template <class List>
struct for_each_type_impl;
template <template <class...> class L, class... Ts>
struct for_each_type_impl<L<Ts...>> {
template <class Fun>
static void exec(Fun const &fun) {
(void)(int[]){((void)fun.template operator()<Ts>(), 0)...};
}
};
} // namespace for_each_detail
/// Calls fun(T{}) for each element of the type list List.
template <class List, class Fun>
void for_each(Fun const &fun) {
for_each_detail::for_each_impl<List>::exec(fun);
};
/// Calls fun.template operator<T>() for each element of the type list List.
///
/// Note the difference between for_each: T is passed only as a template parameter; the operator itself has to
/// be a nullary function. This ensures that the object of type T is nor created, nor passed to the function.
/// The disadvantage is that the functor can not be a [generic] lambda (in C++14 syntax) and also it limits the
/// ability to do operator(). However, if T is not a POD it makes sense to use this for_each flavour. Also
/// nvcc8 has problems with the code generation for the regular for_each even if all the types are empty
/// structs.
template <class List, class Fun>
void for_each_type(Fun const &fun) {
for_each_detail::for_each_type_impl<List>::exec(fun);
}
} // namespace cpp_bindgen
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