Formattable

class U_I18N_API Formattable

Formattable objects can be passed to the Format class or its subclasses for formatting

Public Classes
enum ISDATE: This enum is only used to let callers distinguish between the Formattable(UDate) constructor and the Formattable(double) constructor; the compiler cannot distinguish the signatures, since UDate is currently typedefed to be either double or long
enum Type: The list of possible data types of this Formattable object

Public Methods
Formattable(UDate d, ISDATE): Creates a Formattable object with a UDate instance
Formattable(double d): Creates a Formattable object with a double number
Formattable(int32_t l): Creates a Formattable object with a long number
Formattable(const char* strToCopy): Creates a Formattable object with a char string pointer
Formattable(const UnicodeString& stringToCopy): Creates a Formattable object with a UnicodeString object to copy from
Formattable(UnicodeString* stringToAdopt): Creates a Formattable object with a UnicodeString object to adopt from
Formattable(const Formattable* arrayToCopy, int32_t count): Creates a Formattable object with an array of Formattable objects
Formattable(const Formattable&): Copy constructor
Formattable& operator=(const Formattable&): Assignment operator
bool_t operator==(const Formattable&) const: Equality comparison
virtual ~Formattable(): Destructor
Type getType(void) const: Gets the data type of this Formattable object
double getDouble(void) const: Gets the double value of this object
int32_t getLong(void) const: Gets the long value of this object
UDate getDate(void) const: Gets the Date value of this object
UnicodeString& getString(UnicodeString& result) const: Gets the string value of this object
const Formattable* getArray(int32_t& count) const: Gets the array value and count of this object
Formattable& operator[](int32_t index): Accesses the specified element in the array value of this Formattable object
void setDouble(double d): Sets the double value of this object
void setLong(int32_t l): Sets the long value of this object
void setDate(UDate d): Sets the Date value of this object
void setString(const UnicodeString& stringToCopy): Sets the string value of this object
void setArray(const Formattable* array, int32_t count): Sets the array value and count of this object
void adoptString(UnicodeString* stringToAdopt): Sets and adopts the string value and count of this object
void adoptArray(Formattable* array, int32_t count): Sets and adopts the array value and count of this object

Documentation

Formattable objects can be passed to the Format class or its subclasses for formatting. Formattable is a thin wrapper class which interconverts between the primitive numeric types (double, long, etc.) as well as UDate and UnicodeString.
Note that this is fundamentally different from the Java behavior, since in this case the various formattable objects do not occupy a hierarchy, but are all wrapped within this one class. Formattable encapsulates all the polymorphism in itself.
It would be easy to change this so that Formattable was an abstract base class of a genuine hierarchy, and that would clean up the code that currently must explicitly check for type, but that seems like overkill at this point.