77 lines
1.6 KiB
C++
77 lines
1.6 KiB
C++
#ifndef FURVM_CONSTANT_HPP
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#define FURVM_CONSTANT_HPP
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#include "furvm/exceptions.hpp"
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#include "furvm/fwd.hpp"
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#include <string_view>
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namespace furvm {
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enum class constant_t : std::uint8_t {
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String, /**< String constant. */
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};
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class constant {
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public:
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using string_type = std::string_view; /**< String constant type. */
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public:
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/**
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* @brief Construct a new string constant.
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*
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* @param string String.
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*/
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constant(string_type string)
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: m_type(constant_t::String), m_value(string) {}
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~constant() = default;
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/**
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* @brief Move constructor.
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*/
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constant(constant&&) = default;
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/**
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* @brief Move constructor.
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*/
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constant& operator=(constant&&) = default;
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constant(const constant&) = delete;
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constant& operator=(const constant&) = delete;
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public:
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/**
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* @brief Returns this constant's type.
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* @see constant_t
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*
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* @return The constant type.
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*/
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constexpr constant_t type() const { return m_type; }
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/**
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* @brief Returns this constant's string value.
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* @throws bad_constant_access if this constant's type is not constant_t::String.
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*
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* @return The string value.
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*/
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constexpr string_type string() const {
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require_type(constant_t::String);
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return m_value.string;
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}
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private:
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void require_type(constant_t type) const {
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if (m_type != type) throw bad_constant_access();
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}
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private:
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constant_t m_type{};
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union value {
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string_type string;
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value(string_type sv)
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: string(sv) {}
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} m_value;
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};
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} // namespace furvm
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#endif // FURVM_CONSTANT_HPP
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