You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
109 lines
3.0 KiB
109 lines
3.0 KiB
// Copyright 2019 Google LLC
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// https://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
#ifndef dap_variant_h
|
|
#define dap_variant_h
|
|
|
|
#include "any.h"
|
|
|
|
namespace dap {
|
|
|
|
// internal functionality
|
|
namespace detail {
|
|
template <typename T, typename...>
|
|
struct TypeIsIn {
|
|
static constexpr bool value = false;
|
|
};
|
|
|
|
template <typename T, typename List0, typename... ListN>
|
|
struct TypeIsIn<T, List0, ListN...> {
|
|
static constexpr bool value =
|
|
std::is_same<T, List0>::value || TypeIsIn<T, ListN...>::value;
|
|
};
|
|
} // namespace detail
|
|
|
|
// variant represents a type-safe union of DAP types.
|
|
// variant can hold a value of any of the template argument types.
|
|
// variant defaults to a default-constructed T0.
|
|
template <typename T0, typename... Types>
|
|
class variant {
|
|
public:
|
|
// constructors
|
|
inline variant();
|
|
template <typename T>
|
|
inline variant(const T& val);
|
|
|
|
// assignment
|
|
template <typename T>
|
|
inline variant& operator=(const T& val);
|
|
|
|
// get() returns the contained value of the type T.
|
|
// If the any does not contain a value of type T, then get() will assert.
|
|
template <typename T>
|
|
inline T& get() const;
|
|
|
|
// is() returns true iff the contained value is of type T.
|
|
template <typename T>
|
|
inline bool is() const;
|
|
|
|
// accepts() returns true iff the variant accepts values of type T.
|
|
template <typename T>
|
|
static constexpr bool accepts();
|
|
|
|
private:
|
|
friend class Serializer;
|
|
friend class Deserializer;
|
|
any value;
|
|
};
|
|
|
|
template <typename T0, typename... Types>
|
|
variant<T0, Types...>::variant() : value(T0()) {}
|
|
|
|
template <typename T0, typename... Types>
|
|
template <typename T>
|
|
variant<T0, Types...>::variant(const T& v) : value(v) {
|
|
static_assert(accepts<T>(), "variant does not accept template type T");
|
|
}
|
|
|
|
template <typename T0, typename... Types>
|
|
template <typename T>
|
|
variant<T0, Types...>& variant<T0, Types...>::operator=(const T& v) {
|
|
static_assert(accepts<T>(), "variant does not accept template type T");
|
|
value = v;
|
|
return *this;
|
|
}
|
|
|
|
template <typename T0, typename... Types>
|
|
template <typename T>
|
|
T& variant<T0, Types...>::get() const {
|
|
static_assert(accepts<T>(), "variant does not accept template type T");
|
|
return value.get<T>();
|
|
}
|
|
|
|
template <typename T0, typename... Types>
|
|
template <typename T>
|
|
bool variant<T0, Types...>::is() const {
|
|
return value.is<T>();
|
|
}
|
|
|
|
template <typename T0, typename... Types>
|
|
template <typename T>
|
|
constexpr bool variant<T0, Types...>::accepts() {
|
|
return detail::TypeIsIn<T, T0, Types...>::value;
|
|
}
|
|
|
|
} // namespace dap
|
|
|
|
#endif // dap_variant_h
|