aya/engine/3d/src/enumclass.hpp

/**
  @file enumclass.h

  @maintainer Morgan McGuire, http://graphics.cs.williams.edu
  @created 2007-01-27
  @edited  2007-07-20
*/
#ifndef G3D_enumclass_h
#define G3D_enumclass_h

#include "HashTrait.hpp"

/**
\def G3D_DECLARE_ENUM_CLASS_METHODS

  \brief Creates a series of methods that turn a class into a scoped enumeration.

  Uses the "Intelligent Enum" design pattern
  http://www.codeguru.com/cpp/cpp/cpp_mfc/article.php/c4001/

  Enum classes are initialized to their zero value by default.

  You must implement the following method before calling G3D_DECLARE_ENUM_CLASS_METHODS, as either:

  <pre>
    static const char* toString(int i, Value& v) {
        static const char* str[] = {"FUEL", "FOOD", "WATER", NULL}; // Whatever your enum values are
        static const Value val[] = {FUEL, FOOD, WATER};             // Whatever your enum values are
        const char* s = str[i];
        if (s) {
            v = val[i];
        }
        return s;
    }
  </pre>

  See GLGKey.h for an example.
  \sa G3D_DECLARE_ENUM_CLASS_HASHCODE
 */
#define G3D_DECLARE_ENUM_CLASS_METHODS(Classname) \
private: \
    void fromString(const std::string& x) \
    { \
        Value v; \
        const char* s; \
        int i = 0; \
\
        do \
        { \
            s = toString(i, v); \
            if (x == s) \
            { \
                value = v; \
                return; \
            } \
            ++i; \
        } while (s); \
    } \
\
public: \
    const char* toString() const \
    { \
        const char* s; \
        int i = 0; \
        Value v = (Value)0; \
        while (true) \
        { \
            s = toString(i, v); \
            if ((s == NULL) || (v == value)) \
            { \
                return s; \
            } \
            ++i; \
        } \
        return NULL; \
    } \
\
    explicit Classname(const std::string& x) \
        : value((Value)0) \
    { \
        fromString(x); \
    } \
\
    Classname(char v) \
        : value((Value)v) \
    { \
    } \
\
    Classname() \
        : value((Value)0) \
    { \
    } \
\
    Classname(const Value v) \
        : value(v) \
    { \
    } \
\
    explicit Classname(int v) \
        : value((Value)v) \
    { \
    } \
\
    /** Support cast back to the Value type, which is needed to allow implicit assignment inside unions. */ \
    /*inline operator Value() const { \
        return value; \
        }*/ \
\
    operator int() const \
    { \
        return (int)value; \
    } \
\
    bool operator==(const Classname other) const \
    { \
        return value == other.value; \
    } \
\
    bool operator==(const Classname::Value other) const \
    { \
        return value == other; \
    } \
\
    bool operator!=(const Classname other) const \
    { \
        return value != other.value; \
    } \
\
    bool operator!=(const Classname::Value other) const \
    { \
        return value != other; \
    } \
\
    bool operator<(const Classname other) const \
    { \
        return value < other.value; \
    } \
\
    bool operator>(const Classname other) const \
    { \
        return value > other.value; \
    } \
\
    bool operator>=(const Classname other) const \
    { \
        return value >= other.value; \
    } \
\
    bool operator<=(const Classname other) const \
    { \
        return value <= other.value; \
    } \
\
    bool operator<(const Value other) const \
    { \
        return value < other; \
    } \
\
    bool operator>(const Value other) const \
    { \
        return value > other; \
    } \
\
    bool operator<=(const Value other) const \
    { \
        return value <= other; \
    } \
\
    bool operator>=(const Value other) const \
    { \
        return value >= other; \
    } \
\
    Classname& operator--() \
    { \
        value = (Value)((int)value - 1); \
        return *this; \
    } \
\
    Classname& operator++() \
    { \
        value = (Value)((int)value + 1); \
        return *this; \
    } \
\
    Classname& operator+=(const int x) \
    { \
        value = (Value)((int)value + x); \
        return *this; \
    } \
\
    Classname& operator-=(const int x) \
    { \
        value = (Value)((int)value - x); \
        return *this; \
    } \
\
    Classname operator+(const int x) const \
    { \
        return Classname((int)value + x); \
    } \
\
    Classname operator-(const int x) const \
    { \
        return Classname((int)value - x); \
    } \
\
    unsigned int hashCode() const \
    { \
        return (unsigned int)value; \
    }


/** \def G3D_DECLARE_ENUM_CLASS_HASHCODE
 */
#define G3D_DECLARE_ENUM_CLASS_HASHCODE(Classname) \
    template<> \
    struct HashTrait<Classname::Value> \
    { \
        static size_t hashCode(Classname::Value key) \
        { \
            return static_cast<size_t>(key); \
        } \
    }; \
\
    template<> \
    struct HashTrait<Classname> \
    { \
        static size_t hashCode(Classname key) \
        { \
            return static_cast<size_t>(key.hashCode()); \
        } \
    };

#endif