QIDISlicer1.0.0

src/libslic3r/enum_bitmask.hpp

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+#ifndef slic3r_enum_bitmask_hpp_
+#define slic3r_enum_bitmask_hpp_
+
+// enum_bitmask for passing a set of attributes to a function in a type safe way.
+// Adapted from https://gpfault.net/posts/typesafe-bitmasks.txt.html
+// with hints from https://www.strikerx3.dev/cpp/2019/02/27/typesafe-enum-class-bitmasks-in-cpp.html
+
+#include <type_traits>
+
+namespace Slic3r {
+
+// enum_bitmasks can only be used with enums.
+template<class option_type, typename = typename std::enable_if<std::is_enum<option_type>::value>::type>
+class enum_bitmask {
+    // The type we'll use for storing the value of our bitmask should be the same as the enum's underlying type.
+    using underlying_type = typename std::underlying_type<option_type>::type;
+
+    // This method helps us avoid having to explicitly set enum values to powers of two.
+    static constexpr underlying_type mask_value(option_type o) { return 1 << static_cast<underlying_type>(o); }
+
+    // Private ctor to be used internally.
+    explicit constexpr enum_bitmask(underlying_type o) : m_bits(o) {}
+
+public:
+    // Default ctor creates a bitmask with no options selected.
+    constexpr enum_bitmask() : m_bits(0) {}
+
+    // Creates a enum_bitmask with just one bit set.
+    // This ctor is intentionally non-explicit, to allow passing an options to a function:
+    // FunctionExpectingBitmask(Options::Opt1)
+    constexpr enum_bitmask(option_type o) : m_bits(mask_value(o)) {}
+
+    // Set the bit corresponding to the given option.
+    constexpr enum_bitmask operator|(option_type t) const { return enum_bitmask(m_bits | mask_value(t)); }
+
+    // Combine with another enum_bitmask of the same type.
+    constexpr enum_bitmask operator|(enum_bitmask<option_type> t) const { return enum_bitmask(m_bits | t.m_bits); }
+
+    // Set the bit corresponding to the given option.
+    constexpr void operator|=(option_type t) { m_bits = enum_bitmask(m_bits | mask_value(t)); }
+
+    // Combine with another enum_bitmask of the same type.
+    constexpr void operator|=(enum_bitmask<option_type> t) { m_bits = enum_bitmask(m_bits | t.m_bits); }
+
+    // Get the value of the bit corresponding to the given option.
+    constexpr bool operator&(option_type t) const { return m_bits & mask_value(t); }
+    constexpr bool has(option_type t) const { return m_bits & mask_value(t); }
+
+    constexpr bool operator==(const enum_bitmask r) const { return m_bits == r.m_bits; }
+    constexpr bool operator!=(const enum_bitmask r) const { return m_bits != r.m_bits; }
+    // For sorting by the enum values.
+    constexpr bool lower(const enum_bitmask r) const { return m_bits < r.m_bits; }
+
+private:
+    underlying_type m_bits = 0;
+};
+
+// For enabling free functions producing enum_bitmask<> type from bit operations on enums.
+template<typename Enum> struct is_enum_bitmask_type { static constexpr const bool enable = false; };
+#define ENABLE_ENUM_BITMASK_OPERATORS(x) template<> struct is_enum_bitmask_type<x> { static constexpr const bool enable = true; };
+template<class Enum> inline constexpr bool is_enum_bitmask_type_v = is_enum_bitmask_type<Enum>::enable;
+
+// Creates an enum_bitmask from two options, convenient for passing of options to a function:
+// FunctionExpectingBitmask(Options::Opt1 | Options::Opt2 | Options::Opt3)
+template <class option_type>
+constexpr std::enable_if_t<is_enum_bitmask_type_v<option_type>, enum_bitmask<option_type>> operator|(option_type lhs, option_type rhs) {
+    static_assert(std::is_enum_v<option_type>);
+    return enum_bitmask<option_type>{lhs} | rhs;
+}
+
+template <class option_type>
+constexpr std::enable_if_t<is_enum_bitmask_type_v<option_type>, enum_bitmask<option_type>> operator|(option_type lhs, enum_bitmask<option_type> rhs) {
+    static_assert(std::is_enum_v<option_type>);
+    return enum_bitmask<option_type>{lhs} | rhs;
+}
+
+template <class option_type>
+constexpr std::enable_if_t<is_enum_bitmask_type_v<option_type>, enum_bitmask<option_type>> only_if(bool condition, option_type opt) {
+    static_assert(std::is_enum_v<option_type>);
+    return condition ? enum_bitmask<option_type>{opt} : enum_bitmask<option_type>{};
+}
+
+template <class option_type>
+constexpr std::enable_if_t<is_enum_bitmask_type_v<option_type>, enum_bitmask<option_type>> only_if(bool condition, enum_bitmask<option_type> opt) {
+    static_assert(std::is_enum_v<option_type>);
+    return condition ? opt : enum_bitmask<option_type>{};
+}
+
+} // namespace Slic3r
+
+#endif // slic3r_enum_bitmask_hpp_