724 lines
26 KiB
C++
724 lines
26 KiB
C++
//# This file is a part of toml++ and is subject to the the terms of the MIT license.
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//# Copyright (c) 2019-2020 Mark Gillard <mark.gillard@outlook.com.au>
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//# See https://github.com/marzer/tomlplusplus/blob/master/LICENSE for the full license text.
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// SPDX-License-Identifier: MIT
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#pragma once
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#include "toml_common.h"
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TOML_PUSH_WARNINGS
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TOML_DISABLE_PADDING_WARNINGS
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TOML_DISABLE_MISC_WARNINGS
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#if defined(doxygen) || TOML_SIMPLE_STATIC_ASSERT_MESSAGES
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#define TOML_SA_NEWLINE " "
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#define TOML_SA_LIST_SEP ", "
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#define TOML_SA_LIST_BEG " ("
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#define TOML_SA_LIST_END ")"
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#define TOML_SA_LIST_NEW " "
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#define TOML_SA_LIST_NXT ", "
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#define TOML_SA_LIST_CAP(...)
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#else
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#define TOML_SA_NEWLINE "\n| "
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#define TOML_SA_LIST_SEP TOML_SA_NEWLINE " - "
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#define TOML_SA_LIST_BEG TOML_SA_LIST_SEP
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#define TOML_SA_LIST_END
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#define TOML_SA_LIST_NEW TOML_SA_NEWLINE TOML_SA_NEWLINE
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#define TOML_SA_LIST_NXT TOML_SA_LIST_NEW
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#define TOML_SA_LIST_CAP(val) val
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#endif
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#define TOML_SA_NATIVE_VALUE_TYPE_LIST \
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TOML_SA_LIST_BEG "std::string" \
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TOML_SA_LIST_SEP "int64_t" \
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TOML_SA_LIST_SEP "double" \
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TOML_SA_LIST_SEP "bool" \
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TOML_SA_LIST_SEP "toml::date" \
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TOML_SA_LIST_SEP "toml::time" \
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TOML_SA_LIST_SEP "toml::date_time" \
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TOML_SA_LIST_END
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#define TOML_SA_NODE_TYPE_LIST \
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TOML_SA_LIST_BEG "toml::table" \
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TOML_SA_LIST_SEP "toml::array" \
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TOML_SA_LIST_SEP "toml::value<std::string>" \
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TOML_SA_LIST_SEP "toml::value<int64_t>" \
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TOML_SA_LIST_SEP "toml::value<double>" \
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TOML_SA_LIST_SEP "toml::value<bool>" \
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TOML_SA_LIST_SEP "toml::value<toml::date>" \
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TOML_SA_LIST_SEP "toml::value<toml::time>" \
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TOML_SA_LIST_SEP "toml::value<toml::date_time>" \
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TOML_SA_LIST_END
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#define TOML_SA_UNWRAPPED_NODE_TYPE_LIST \
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TOML_SA_LIST_NEW "A native TOML value type" \
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TOML_SA_NATIVE_VALUE_TYPE_LIST \
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\
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TOML_SA_LIST_NXT "A TOML node type" \
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TOML_SA_NODE_TYPE_LIST
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TOML_NAMESPACE_START
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{
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/// \brief A TOML node.
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///
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/// \detail A parsed TOML document forms a tree made up of tables, arrays and values.
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/// This type is the base of each of those, providing a lot of the polymorphic plumbing.
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class TOML_INTERFACE TOML_API node
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{
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private:
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friend class TOML_PARSER_TYPENAME;
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source_region source_{};
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protected:
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node() noexcept = default;
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node(const node&) noexcept = default;
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node(node&& other) noexcept;
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node& operator= (const node&) noexcept = default;
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node& operator= (node&& rhs) noexcept;
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template <typename T>
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[[nodiscard]]
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TOML_ALWAYS_INLINE
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impl::wrap_node<T>& ref_cast() & noexcept
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{
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return *reinterpret_cast<impl::wrap_node<T>*>(this);
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}
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template <typename T>
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[[nodiscard]]
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TOML_ALWAYS_INLINE
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impl::wrap_node<T>&& ref_cast() && noexcept
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{
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return std::move(*reinterpret_cast<impl::wrap_node<T>*>(this));
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}
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template <typename T>
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[[nodiscard]]
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TOML_ALWAYS_INLINE
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const impl::wrap_node<T>& ref_cast() const & noexcept
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{
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return *reinterpret_cast<const impl::wrap_node<T>*>(this);
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}
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template <typename N, typename T>
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using ref_cast_type = decltype(std::declval<N>().template ref_cast<T>());
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public:
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virtual ~node() noexcept = default;
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/// \brief Returns the node's type identifier.
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[[nodiscard]] virtual node_type type() const noexcept = 0;
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/// \brief Returns true if this node is a table.
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[[nodiscard]] virtual bool is_table() const noexcept = 0;
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/// \brief Returns true if this node is an array.
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[[nodiscard]] virtual bool is_array() const noexcept = 0;
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/// \brief Returns true if this node is a value.
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[[nodiscard]] virtual bool is_value() const noexcept = 0;
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/// \brief Returns true if this node is a string value.
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[[nodiscard]] virtual bool is_string() const noexcept;
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/// \brief Returns true if this node is an integer value.
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[[nodiscard]] virtual bool is_integer() const noexcept;
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/// \brief Returns true if this node is an floating-point value.
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[[nodiscard]] virtual bool is_floating_point() const noexcept;
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/// \brief Returns true if this node is an integer or floating-point value.
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[[nodiscard]] virtual bool is_number() const noexcept;
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/// \brief Returns true if this node is a boolean value.
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[[nodiscard]] virtual bool is_boolean() const noexcept;
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/// \brief Returns true if this node is a local date value.
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[[nodiscard]] virtual bool is_date() const noexcept;
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/// \brief Returns true if this node is a local time value.
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[[nodiscard]] virtual bool is_time() const noexcept;
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/// \brief Returns true if this node is a date-time value.
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[[nodiscard]] virtual bool is_date_time() const noexcept;
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/// \brief Returns true if this node is an array containing only tables.
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[[nodiscard]] virtual bool is_array_of_tables() const noexcept;
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/// \brief Checks if a node is a specific type.
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///
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/// \tparam T A TOML node or value type.
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///
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/// \returns Returns true if this node is an instance of the specified type.
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template <typename T>
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[[nodiscard]]
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bool is() const noexcept
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{
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using type = impl::unwrap_node<T>;
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static_assert(
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(impl::is_native<type> || impl::is_one_of<type, table, array>) && !impl::is_cvref<type>,
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"The template type argument of node::is() must be one of:"
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TOML_SA_UNWRAPPED_NODE_TYPE_LIST
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);
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if constexpr (std::is_same_v<type, table>) return is_table();
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else if constexpr (std::is_same_v<type, array>) return is_array();
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else if constexpr (std::is_same_v<type, std::string>) return is_string();
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else if constexpr (std::is_same_v<type, int64_t>) return is_integer();
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else if constexpr (std::is_same_v<type, double>) return is_floating_point();
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else if constexpr (std::is_same_v<type, bool>) return is_boolean();
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else if constexpr (std::is_same_v<type, date>) return is_date();
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else if constexpr (std::is_same_v<type, time>) return is_time();
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else if constexpr (std::is_same_v<type, date_time>) return is_date_time();
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}
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/// \brief Returns a pointer to the node as a toml::table, if it is one.
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[[nodiscard]] virtual table* as_table() noexcept;
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/// \brief Returns a pointer to the node as a toml::array, if it is one.
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[[nodiscard]] virtual array* as_array() noexcept;
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/// \brief Returns a pointer to the node as a toml::value<string>, if it is one.
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[[nodiscard]] virtual toml::value<std::string>* as_string() noexcept;
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/// \brief Returns a pointer to the node as a toml::value<int64_t>, if it is one.
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[[nodiscard]] virtual toml::value<int64_t>* as_integer() noexcept;
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/// \brief Returns a pointer to the node as a toml::value<double>, if it is one.
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[[nodiscard]] virtual toml::value<double>* as_floating_point() noexcept;
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/// \brief Returns a pointer to the node as a toml::value<bool>, if it is one.
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[[nodiscard]] virtual toml::value<bool>* as_boolean() noexcept;
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/// \brief Returns a pointer to the node as a toml::value<date>, if it is one.
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[[nodiscard]] virtual toml::value<date>* as_date() noexcept;
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/// \brief Returns a pointer to the node as a toml::value<time>, if it is one.
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[[nodiscard]] virtual toml::value<time>* as_time() noexcept;
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/// \brief Returns a pointer to the node as a toml::value<date_time>, if it is one.
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[[nodiscard]] virtual toml::value<date_time>* as_date_time() noexcept;
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[[nodiscard]] virtual const table* as_table() const noexcept;
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[[nodiscard]] virtual const array* as_array() const noexcept;
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[[nodiscard]] virtual const toml::value<std::string>* as_string() const noexcept;
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[[nodiscard]] virtual const toml::value<int64_t>* as_integer() const noexcept;
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[[nodiscard]] virtual const toml::value<double>* as_floating_point() const noexcept;
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[[nodiscard]] virtual const toml::value<bool>* as_boolean() const noexcept;
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[[nodiscard]] virtual const toml::value<date>* as_date() const noexcept;
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[[nodiscard]] virtual const toml::value<time>* as_time() const noexcept;
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[[nodiscard]] virtual const toml::value<date_time>* as_date_time() const noexcept;
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private:
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#ifndef DOXYGEN
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template <typename T>
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[[nodiscard]]
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decltype(auto) get_value_exact() const noexcept;
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#endif // !DOXYGEN
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public:
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/// \brief Gets the value contained by this node.
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///
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/// \detail This function has 'exact' retrieval semantics; the only return value types allowed are the
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/// TOML native value types, or types that can losslessly represent a native value type (e.g.
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/// std::wstring on Windows).
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///
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/// \tparam T One of the native TOML value types, or a type capable of losslessly representing one.
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///
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/// \returns The underlying value if the node was a value of the
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/// matching type (or losslessly convertible to it), or an empty optional.
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///
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/// \see node::value()
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template <typename T>
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[[nodiscard]]
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optional<T> value_exact() const noexcept;
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/// \brief Gets the value contained by this node.
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///
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/// \detail This function has 'permissive' retrieval semantics; some value types are allowed
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/// to convert to others (e.g. retrieving a boolean as an integer), and the specified return value
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/// type can be any type where a reasonable conversion from a native TOML value exists
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/// (e.g. std::wstring on Windows). If the source value cannot be represented by
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/// the destination type, an empty optional is returned.
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///
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/// \cpp
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/// auto tbl = toml::parse(R"(
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/// int = -10
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/// flt = 25.0
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/// pi = 3.14159
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/// bool = false
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/// huge = 9223372036854775807
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/// str = "foo"
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/// )"sv);
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///
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/// const auto print_value_with_typename =
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/// [&](std::string_view key, std::string_view type_name, auto* dummy)
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/// {
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/// std::cout << "'" << key << "' as " << type_name << ": ";
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/// using type = std::remove_pointer_t<decltype(dummy)>;
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/// if (std::optional<type> val = tbl.get(key)->value<type>())
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/// std::cout << *val << "\n";
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/// else
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/// std::cout << "No conversion path or out-of-range\n";
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/// };
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///
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/// #define print_value(key, T) print_value_with_typename(key, #T, (T*)nullptr)
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///
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/// print_value("int", bool);
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/// print_value("int", int);
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/// print_value("int", unsigned int);
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/// print_value("int", long long);
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/// print_value("int", float);
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/// print_value("int", double);
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/// std::cout << "\n";
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///
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/// print_value("flt", bool);
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/// print_value("flt", int);
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/// print_value("flt", unsigned int);
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/// print_value("flt", long long);
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/// print_value("flt", float);
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/// print_value("flt", double);
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/// std::cout << "\n";
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///
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/// print_value("pi", bool);
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/// print_value("pi", int);
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/// print_value("pi", unsigned int);
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/// print_value("pi", long long);
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/// print_value("pi", float);
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/// print_value("pi", double);
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/// std::cout << "\n";
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///
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/// print_value("bool", bool);
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/// print_value("bool", int);
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/// print_value("bool", unsigned int);
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/// print_value("bool", long long);
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/// print_value("bool", float);
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/// print_value("bool", double);
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/// std::cout << "\n";
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///
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/// print_value("huge", bool);
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/// print_value("huge", int);
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/// print_value("huge", unsigned int);
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/// print_value("huge", long long);
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/// print_value("huge", float);
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/// print_value("huge", double);
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/// std::cout << "\n";
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///
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/// print_value("str", std::string);
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/// print_value("str", std::string_view);
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/// print_value("str", const char*);
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/// std::cout << "\n";
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/// \ecpp
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///
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/// \out
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/// 'int' as bool: true
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/// 'int' as int: -10
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/// 'int' as unsigned int: No conversion path or out-of-range
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/// 'int' as long long: -10
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/// 'int' as float: -10
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/// 'int' as double: -10
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///
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/// 'flt' as bool: No conversion path or out-of-range
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/// 'flt' as int: 25
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/// 'flt' as unsigned int: 25
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/// 'flt' as long long: 25
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/// 'flt' as float: 25
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/// 'flt' as double: 25
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///
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/// 'pi' as bool: No conversion path or out-of-range
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/// 'pi' as int: No conversion path or out-of-range
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/// 'pi' as unsigned int: No conversion path or out-of-range
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/// 'pi' as long long: No conversion path or out-of-range
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/// 'pi' as float: 3.14159
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/// 'pi' as double: 3.14159
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///
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/// 'bool' as bool: false
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/// 'bool' as int: 0
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/// 'bool' as unsigned int: 0
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/// 'bool' as long long: 0
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/// 'bool' as float: No conversion path or out-of-range
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/// 'bool' as double: No conversion path or out-of-range
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///
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/// 'huge' as bool: true
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/// 'huge' as int: No conversion path or out-of-range
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/// 'huge' as unsigned int: No conversion path or out-of-range
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/// 'huge' as long long: 9223372036854775807
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/// 'huge' as float: No conversion path or out-of-range
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/// 'huge' as double: No conversion path or out-of-range
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///
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/// 'str' as std::string: foo
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/// 'str' as std::string_view: foo
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/// 'str' as const char*: foo
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/// \eout
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///
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/// \tparam T One of the native TOML value types, or a type capable of converting to one.
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///
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/// \returns The underlying value if the node was a value of the matching type (or convertible to it)
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/// and within the range of the output type, or an empty optional.
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///
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/// \attention If you want strict value retrieval semantics that do not allow for any type conversions,
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/// use node::value_exact() instead.
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///
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/// \see node::value_exact()
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template <typename T>
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[[nodiscard]]
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optional<T> value() const noexcept;
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/// \brief Gets the raw value contained by this node, or a default.
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///
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/// \tparam T Default value type. Must be one of the native TOML value types,
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/// or convertible to it.
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/// \param default_value The default value to return if the node wasn't a value, wasn't the
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/// correct type, or no conversion was possible.
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///
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/// \returns The underlying value if the node was a value of the matching type (or convertible to it)
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/// and within the range of the output type, or the provided default.
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///
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/// \attention This function has the same permissive retrieval semantics as node::value(). If you want strict
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/// value retrieval semantics that do not allow for any type conversions, use node::value_exact()
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/// instead.
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///
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/// \see
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/// - node::value()
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/// - node::value_exact()
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template <typename T>
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[[nodiscard]]
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auto value_or(T&& default_value) const noexcept;
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/// \brief Gets a pointer to the node as a more specific node type.
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///
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/// \details \cpp
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///
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/// toml::value<int64_t>* int_value = node->as<int64_t>();
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/// toml::table* tbl = node->as<toml::table>();
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/// if (int_value)
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/// std::cout << "Node is a value<int64_t>" << std::endl;
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/// else if (tbl)
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/// std::cout << "Node is a table" << std::endl;
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///
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/// // fully-qualified value node types also work (useful for template code):
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/// toml::value<int64_t>* int_value2 = node->as<toml::value<int64_t>>();
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/// if (int_value2)
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/// std::cout << "Node is a value<int64_t>" << std::endl;
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///
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/// \ecpp
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///
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/// \tparam T The node type or TOML value type to cast to.
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///
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/// \returns A pointer to the node as the given type, or nullptr if it was a different type.
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template <typename T>
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[[nodiscard]]
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impl::wrap_node<T>* as() noexcept
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{
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using type = impl::unwrap_node<T>;
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static_assert(
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(impl::is_native<type> || impl::is_one_of<type, table, array>) && !impl::is_cvref<type>,
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"The template type argument of node::as() must be one of:"
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TOML_SA_UNWRAPPED_NODE_TYPE_LIST
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);
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if constexpr (std::is_same_v<type, table>) return as_table();
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else if constexpr (std::is_same_v<type, array>) return as_array();
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else if constexpr (std::is_same_v<type, std::string>) return as_string();
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else if constexpr (std::is_same_v<type, int64_t>) return as_integer();
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else if constexpr (std::is_same_v<type, double>) return as_floating_point();
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else if constexpr (std::is_same_v<type, bool>) return as_boolean();
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else if constexpr (std::is_same_v<type, date>) return as_date();
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else if constexpr (std::is_same_v<type, time>) return as_time();
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else if constexpr (std::is_same_v<type, date_time>) return as_date_time();
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}
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/// \brief Gets a pointer to the node as a more specific node type (const overload).
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template <typename T>
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[[nodiscard]]
|
|
const impl::wrap_node<T>* as() const noexcept
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|
{
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using type = impl::unwrap_node<T>;
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|
static_assert(
|
|
(impl::is_native<type> || impl::is_one_of<type, table, array>) && !impl::is_cvref<type>,
|
|
"The template type argument of node::as() must be one of:"
|
|
TOML_SA_UNWRAPPED_NODE_TYPE_LIST
|
|
);
|
|
|
|
if constexpr (std::is_same_v<type, table>) return as_table();
|
|
else if constexpr (std::is_same_v<type, array>) return as_array();
|
|
else if constexpr (std::is_same_v<type, std::string>) return as_string();
|
|
else if constexpr (std::is_same_v<type, int64_t>) return as_integer();
|
|
else if constexpr (std::is_same_v<type, double>) return as_floating_point();
|
|
else if constexpr (std::is_same_v<type, bool>) return as_boolean();
|
|
else if constexpr (std::is_same_v<type, date>) return as_date();
|
|
else if constexpr (std::is_same_v<type, time>) return as_time();
|
|
else if constexpr (std::is_same_v<type, date_time>) return as_date_time();
|
|
}
|
|
|
|
/// \brief Returns the source region responsible for generating this node during parsing.
|
|
[[nodiscard]] const source_region& source() const noexcept;
|
|
|
|
private:
|
|
|
|
template <typename Func, typename N, typename T>
|
|
static constexpr bool can_visit = std::is_invocable_v<Func, ref_cast_type<N, T>>;
|
|
|
|
template <typename Func, typename N>
|
|
static constexpr bool can_visit_any =
|
|
can_visit<Func, N, table>
|
|
|| can_visit<Func, N, array>
|
|
|| can_visit<Func, N, std::string>
|
|
|| can_visit<Func, N, int64_t>
|
|
|| can_visit<Func, N, double>
|
|
|| can_visit<Func, N, bool>
|
|
|| can_visit<Func, N, date>
|
|
|| can_visit<Func, N, time>
|
|
|| can_visit<Func, N, date_time>;
|
|
|
|
template <typename Func, typename N>
|
|
static constexpr bool can_visit_all =
|
|
can_visit<Func, N, table>
|
|
&& can_visit<Func, N, array>
|
|
&& can_visit<Func, N, std::string>
|
|
&& can_visit<Func, N, int64_t>
|
|
&& can_visit<Func, N, double>
|
|
&& can_visit<Func, N, bool>
|
|
&& can_visit<Func, N, date>
|
|
&& can_visit<Func, N, time>
|
|
&& can_visit<Func, N, date_time>;
|
|
|
|
template <typename Func, typename N, typename T>
|
|
static constexpr bool visit_is_nothrow_one =
|
|
!can_visit<Func, N, T>
|
|
|| std::is_nothrow_invocable_v<Func, ref_cast_type<N, T>>;
|
|
|
|
template <typename Func, typename N>
|
|
static constexpr bool visit_is_nothrow =
|
|
visit_is_nothrow_one<Func, N, table>
|
|
&& visit_is_nothrow_one<Func, N, array>
|
|
&& visit_is_nothrow_one<Func, N, std::string>
|
|
&& visit_is_nothrow_one<Func, N, int64_t>
|
|
&& visit_is_nothrow_one<Func, N, double>
|
|
&& visit_is_nothrow_one<Func, N, bool>
|
|
&& visit_is_nothrow_one<Func, N, date>
|
|
&& visit_is_nothrow_one<Func, N, time>
|
|
&& visit_is_nothrow_one<Func, N, date_time>;
|
|
|
|
template <typename Func, typename N, typename T, bool = can_visit<Func, N, T>>
|
|
struct visit_return_type final
|
|
{
|
|
using type = decltype(std::declval<Func>()(std::declval<ref_cast_type<N, T>>()));
|
|
};
|
|
template <typename Func, typename N, typename T>
|
|
struct visit_return_type<Func, N, T, false> final
|
|
{
|
|
using type = void;
|
|
};
|
|
|
|
template <typename A, typename B>
|
|
using nonvoid = std::conditional_t<std::is_void_v<A>, B, A>;
|
|
|
|
//# these functions are static helpers to preserve const and ref categories
|
|
//# (otherwise I'd have to implement them thrice)
|
|
//# ((propagation in C++: a modern horror story))
|
|
|
|
template <typename N, typename Func>
|
|
static decltype(auto) do_visit(N&& n, Func&& visitor)
|
|
noexcept(visit_is_nothrow<Func&&, N&&>)
|
|
{
|
|
static_assert(
|
|
can_visit_any<Func&&, N&&>,
|
|
"TOML node visitors must be invocable for at least one of the toml::node specializations:"
|
|
TOML_SA_NODE_TYPE_LIST
|
|
);
|
|
|
|
switch (n.type())
|
|
{
|
|
case node_type::table:
|
|
if constexpr (can_visit<Func&&, N&&, table>)
|
|
return std::forward<Func>(visitor)(std::forward<N>(n).template ref_cast<table>());
|
|
break;
|
|
|
|
case node_type::array:
|
|
if constexpr (can_visit<Func&&, N&&, array>)
|
|
return std::forward<Func>(visitor)(std::forward<N>(n).template ref_cast<array>());
|
|
break;
|
|
|
|
case node_type::string:
|
|
if constexpr (can_visit<Func&&, N&&, std::string>)
|
|
return std::forward<Func>(visitor)(std::forward<N>(n).template ref_cast<std::string>());
|
|
break;
|
|
|
|
case node_type::integer:
|
|
if constexpr (can_visit<Func&&, N&&, int64_t>)
|
|
return std::forward<Func>(visitor)(std::forward<N>(n).template ref_cast<int64_t>());
|
|
break;
|
|
|
|
case node_type::floating_point:
|
|
if constexpr (can_visit<Func&&, N&&, double>)
|
|
return std::forward<Func>(visitor)(std::forward<N>(n).template ref_cast<double>());
|
|
break;
|
|
|
|
case node_type::boolean:
|
|
if constexpr (can_visit<Func&&, N&&, bool>)
|
|
return std::forward<Func>(visitor)(std::forward<N>(n).template ref_cast<bool>());
|
|
break;
|
|
|
|
case node_type::date:
|
|
if constexpr (can_visit<Func&&, N&&, date>)
|
|
return std::forward<Func>(visitor)(std::forward<N>(n).template ref_cast<date>());
|
|
break;
|
|
|
|
case node_type::time:
|
|
if constexpr (can_visit<Func&&, N&&, time>)
|
|
return std::forward<Func>(visitor)(std::forward<N>(n).template ref_cast<time>());
|
|
break;
|
|
|
|
case node_type::date_time:
|
|
if constexpr (can_visit<Func&&, N&&, date_time>)
|
|
return std::forward<Func>(visitor)(std::forward<N>(n).template ref_cast<date_time>());
|
|
break;
|
|
|
|
case node_type::none: TOML_UNREACHABLE;
|
|
TOML_NO_DEFAULT_CASE;
|
|
}
|
|
|
|
if constexpr (can_visit_all<Func&&, N&&>)
|
|
TOML_UNREACHABLE;
|
|
else
|
|
{
|
|
using return_type =
|
|
nonvoid<typename visit_return_type<Func&&, N&&, table>::type,
|
|
nonvoid<typename visit_return_type<Func&&, N&&, array>::type,
|
|
nonvoid<typename visit_return_type<Func&&, N&&, std::string>::type,
|
|
nonvoid<typename visit_return_type<Func&&, N&&, int64_t>::type,
|
|
nonvoid<typename visit_return_type<Func&&, N&&, double>::type,
|
|
nonvoid<typename visit_return_type<Func&&, N&&, bool>::type,
|
|
nonvoid<typename visit_return_type<Func&&, N&&, date>::type,
|
|
nonvoid<typename visit_return_type<Func&&, N&&, time>::type,
|
|
typename visit_return_type<Func&&, N&&, date_time>::type
|
|
>>>>>>>>;
|
|
|
|
if constexpr (!std::is_void_v<return_type>)
|
|
{
|
|
static_assert(
|
|
std::is_default_constructible_v<return_type>,
|
|
"Non-exhaustive visitors must return a default-constructible type, or void"
|
|
);
|
|
return return_type{};
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
template <typename T, typename N>
|
|
[[nodiscard]]
|
|
static decltype(auto) do_ref(N&& n) noexcept
|
|
{
|
|
using type = impl::unwrap_node<T>;
|
|
static_assert(
|
|
(impl::is_native<type> || impl::is_one_of<type, table, array>) && !impl::is_cvref<type>,
|
|
"The template type argument of node::ref() must be one of:"
|
|
TOML_SA_UNWRAPPED_NODE_TYPE_LIST
|
|
);
|
|
TOML_ASSERT(
|
|
n.template is<T>()
|
|
&& "template type argument T provided to toml::node::ref() didn't match the node's actual type"
|
|
);
|
|
if constexpr (impl::is_native<type>)
|
|
return std::forward<N>(n).template ref_cast<type>().get();
|
|
else
|
|
return std::forward<N>(n).template ref_cast<type>();
|
|
}
|
|
|
|
public:
|
|
|
|
/// \brief Invokes a visitor on the node based on the node's concrete type.
|
|
///
|
|
/// \details Visitation is useful when you expect
|
|
/// a node to be one of a set number of types and need
|
|
/// to handle these types differently. Using `visit()` allows
|
|
/// you to eliminate some of the casting/conversion boilerplate: \cpp
|
|
///
|
|
/// node.visit([](auto&& n)
|
|
/// {
|
|
/// if constexpr (toml::is_string<decltype(n)>)
|
|
/// do_something_with_a_string(*n)); //n is a toml::value<std::string>
|
|
/// else if constexpr (toml::is_integer<decltype(n)>)
|
|
/// do_something_with_an_int(*n); //n is a toml::value<int64_t>
|
|
/// else
|
|
/// throw std::exception{ "Expected string or integer" };
|
|
/// });
|
|
///
|
|
/// \ecpp
|
|
///
|
|
/// \tparam Func A callable type invocable with one or more of the
|
|
/// toml++ node types.
|
|
///
|
|
/// \param visitor The visitor object.
|
|
///
|
|
/// \returns The return value of the visitor.
|
|
/// Can be void. Non-exhaustive visitors must return a default-constructible type.
|
|
///
|
|
/// \see https://en.wikipedia.org/wiki/Visitor_pattern
|
|
template <typename Func>
|
|
decltype(auto) visit(Func&& visitor) &
|
|
noexcept(visit_is_nothrow<Func&&, node&>)
|
|
{
|
|
return do_visit(*this, std::forward<Func>(visitor));
|
|
}
|
|
|
|
/// \brief Invokes a visitor on the node based on the node's concrete type (rvalue overload).
|
|
template <typename Func>
|
|
decltype(auto) visit(Func&& visitor) &&
|
|
noexcept(visit_is_nothrow<Func&&, node&&>)
|
|
{
|
|
return do_visit(std::move(*this), std::forward<Func>(visitor));
|
|
}
|
|
|
|
/// \brief Invokes a visitor on the node based on the node's concrete type (const lvalue overload).
|
|
template <typename Func>
|
|
decltype(auto) visit(Func&& visitor) const&
|
|
noexcept(visit_is_nothrow<Func&&, const node&>)
|
|
{
|
|
return do_visit(*this, std::forward<Func>(visitor));
|
|
}
|
|
|
|
/// \brief Gets a raw reference to a value node's underlying data.
|
|
///
|
|
/// \warning This function is dangerous if used carelessly and **WILL** break your code if the
|
|
/// chosen value type doesn't match the node's actual type. In debug builds an assertion
|
|
/// will fire when invalid accesses are attempted: \cpp
|
|
///
|
|
/// auto tbl = toml::parse(R"(
|
|
/// min = 32
|
|
/// max = 45
|
|
/// )"sv);
|
|
///
|
|
/// int64_t& min_ref = tbl.get("min")->ref<int64_t>(); // matching type
|
|
/// double& max_ref = tbl.get("max")->ref<double>(); // mismatched type, hits assert()
|
|
///
|
|
/// \ecpp
|
|
///
|
|
/// \tparam T One of the TOML value types.
|
|
///
|
|
/// \returns A reference to the underlying data.
|
|
template <typename T>
|
|
[[nodiscard]]
|
|
impl::unwrap_node<T>& ref() & noexcept
|
|
{
|
|
return do_ref<T>(*this);
|
|
}
|
|
|
|
/// \brief Gets a raw reference to a value node's underlying data (rvalue overload).
|
|
template <typename T>
|
|
[[nodiscard]]
|
|
impl::unwrap_node<T>&& ref() && noexcept
|
|
{
|
|
return do_ref<T>(std::move(*this));
|
|
}
|
|
|
|
/// \brief Gets a raw reference to a value node's underlying data (const lvalue overload).
|
|
template <typename T>
|
|
[[nodiscard]]
|
|
const impl::unwrap_node<T>& ref() const& noexcept
|
|
{
|
|
return do_ref<T>(*this);
|
|
}
|
|
};
|
|
}
|
|
TOML_NAMESPACE_END
|
|
|
|
TOML_POP_WARNINGS // TOML_DISABLE_PADDING_WARNINGS, TOML_DISABLE_MISC_WARNINGS
|
|
|