cppdap/include/dap/variant.h
Ben Clayton 9d3f5c8f1d clang: Enable -Weverything, fix all warnings
This change fixes the following warnings:

```
    -Wc++98-compat-extra-semi
    -Wc++98-compat-local-type-template-args
    -Wc++98-compat-pedantic
    -Wc++98-compat
    -Wcomma
    -Wdeprecated-copy-dtor
    -Wexit-time-destructors
    -Wextra-semi-stmt
    -Wextra-semi
    -Wfloat-conversion
    -Wfloat-equal
    -Wformat-nonliteral
    -Wglobal-constructors
    -Winconsistent-missing-destructor-override
    -Wnon-virtual-dtor
    -Wold-style-cast
    -Wpadded
    -Wreturn-std-move-in-c++11
    -Wshadow-field-in-constructor
    -Wshadow-uncaptured-local
    -Wshift-sign-overflow
    -Wsign-conversion
    -Wundef
    -Wunreachable-code-return
    -Wused-but-marked-unused
    -Wweak-vtables
    -Wzero-as-null-pointer-constant
```
2020-06-10 15:10:57 +01:00

109 lines
3.0 KiB
C++

// 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