--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/include/unicode/numfmt.h	Tue Mar 18 17:55:14 2025 -0400
@@ -0,0 +1,1271 @@
+// © 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+********************************************************************************
+* Copyright (C) 1997-2016, International Business Machines Corporation and others.
+* All Rights Reserved.
+********************************************************************************
+*
+* File NUMFMT.H
+*
+* Modification History:
+*
+*   Date        Name        Description
+*   02/19/97    aliu        Converted from java.
+*   03/18/97    clhuang     Updated per C++ implementation.
+*   04/17/97    aliu        Changed DigitCount to int per code review.
+*    07/20/98    stephen        JDK 1.2 sync up. Added scientific support.
+*                            Changed naming conventions to match C++ guidelines
+*                            Derecated Java style constants (eg, INTEGER_FIELD)
+********************************************************************************
+*/
+
+#ifndef NUMFMT_H
+#define NUMFMT_H
+
+
+#include "unicode/utypes.h"
+
+#if U_SHOW_CPLUSPLUS_API
+
+/**
+ * \file
+ * \brief C++ API: Compatibility APIs for number formatting.
+ */
+
+#if !UCONFIG_NO_FORMATTING
+
+#include "unicode/unistr.h"
+#include "unicode/format.h"
+#include "unicode/unum.h" // UNumberFormatStyle
+#include "unicode/locid.h"
+#include "unicode/stringpiece.h"
+#include "unicode/curramt.h"
+#include "unicode/udisplaycontext.h"
+
+class NumberFormatTest;
+
+U_NAMESPACE_BEGIN
+
+class SharedNumberFormat;
+
+#if !UCONFIG_NO_SERVICE
+class NumberFormatFactory;
+class StringEnumeration;
+#endif
+
+/**
+ * <p><strong>IMPORTANT:</strong> New users are strongly encouraged to see if
+ * numberformatter.h fits their use case.  Although not deprecated, this header
+ * is provided for backwards compatibility only.
+ *
+ * Abstract base class for all number formats.  Provides interface for
+ * formatting and parsing a number.  Also provides methods for
+ * determining which locales have number formats, and what their names
+ * are.
+ *
+ * \headerfile unicode/numfmt.h "unicode/numfmt.h"
+ * <P>
+ * NumberFormat helps you to format and parse numbers for any locale.
+ * Your code can be completely independent of the locale conventions
+ * for decimal points, thousands-separators, or even the particular
+ * decimal digits used, or whether the number format is even decimal.
+ * <P>
+ * To format a number for the current Locale, use one of the static
+ * factory methods:
+ * \code
+ *    #include <iostream>
+ *    #include "unicode/numfmt.h"
+ *    #include "unicode/unistr.h"
+ *    #include "unicode/ustream.h"
+ *    using namespace std;
+ *    
+ *    int main() {
+ *        double myNumber = 7.0;
+ *        UnicodeString myString;
+ *        UErrorCode success = U_ZERO_ERROR;
+ *        NumberFormat* nf = NumberFormat::createInstance(success);
+ *        nf->format(myNumber, myString);
+ *        cout << " Example 1: " << myString << endl;
+ *    }
+ * \endcode
+ * Note that there are additional factory methods within subclasses of
+ * NumberFormat.
+ * <P>
+ * If you are formatting multiple numbers, it is more efficient to get
+ * the format and use it multiple times so that the system doesn't
+ * have to fetch the information about the local language and country
+ * conventions multiple times.
+ * \code
+ *     UnicodeString myString;
+ *     UErrorCode success = U_ZERO_ERROR;
+ *     NumberFormat *nf = NumberFormat::createInstance( success );
+ *     for (int32_t number: {123, 3333, -1234567}) {
+ *         nf->format(number, myString);
+ *         myString += "; ";
+ *     }
+ *     cout << " Example 2: " << myString << endl;
+ * \endcode
+ * To format a number for a different Locale, specify it in the
+ * call to \c createInstance().
+ * \code
+ *     nf = NumberFormat::createInstance(Locale::getFrench(), success);
+ * \endcode
+ * You can use a \c NumberFormat to parse also.
+ * \code
+ *    UErrorCode success;
+ *    Formattable result(-999);  // initialized with error code
+ *    nf->parse(myString, result, success);
+ * \endcode
+ * Use \c createInstance() to get the normal number format for a \c Locale.
+ * There are other static factory methods available.  Use \c createCurrencyInstance()
+ * to get the currency number format for that country.  Use \c createPercentInstance()
+ * to get a format for displaying percentages. With this format, a
+ * fraction from 0.53 is displayed as 53%.
+ * <P>
+ * The type of number formatting can be specified by passing a 'style' parameter to \c createInstance().
+ * For example, use\n
+ * \c createInstance(locale, UNUM_DECIMAL, errorCode) to get the normal number format,\n
+ * \c createInstance(locale, UNUM_PERCENT, errorCode) to get a format for displaying percentage,\n
+ * \c createInstance(locale, UNUM_SCIENTIFIC, errorCode) to get a format for displaying scientific number,\n
+ * \c createInstance(locale, UNUM_CURRENCY, errorCode) to get the currency number format,
+ * in which the currency is represented by its symbol, for example, "$3.00".\n
+ * \c createInstance(locale, UNUM_CURRENCY_ISO, errorCode)  to get the currency number format,
+ * in which the currency is represented by its ISO code, for example "USD3.00".\n
+ * \c createInstance(locale, UNUM_CURRENCY_PLURAL, errorCode) to get the currency number format,
+ * in which the currency is represented by its full name in plural format,
+ * for example, "3.00 US dollars" or "1.00 US dollar".
+ * <P>
+ * You can also control the display of numbers with such methods as
+ * \c getMinimumFractionDigits().  If you want even more control over the
+ * format or parsing, or want to give your users more control, you can
+ * try dynamic_casting the \c NumberFormat you get from the factory methods to a
+ * \c DecimalFormat. This will work for the vast majority of
+ * countries; just remember to test for NULL in case you
+ * encounter an unusual one.
+ * <P>
+ * You can also use forms of the parse and format methods with
+ * \c ParsePosition and \c FieldPosition to allow you to:
+ * <ul type=round>
+ *   <li>(a) progressively parse through pieces of a string.
+ *   <li>(b) align the decimal point and other areas.
+ * </ul>
+ * For example, you can align numbers in two ways.
+ * <P>
+ * If you are using a monospaced font with spacing for alignment, you
+ * can pass the \c FieldPosition in your format call, with field =
+ * \c UNUM_INTEGER_FIELD. On output, \c getEndIndex will be set to the offset
+ * between the last character of the integer and the decimal. Add
+ * (desiredSpaceCount - getEndIndex) spaces at the front of the
+ * string.
+ * <P>
+ * If you are using proportional fonts, instead of padding with
+ * spaces, measure the width of the string in pixels from the start to
+ * getEndIndex.  Then move the pen by (desiredPixelWidth -
+ * widthToAlignmentPoint) before drawing the text.  It also works
+ * where there is no decimal, but possibly additional characters at
+ * the end, e.g. with parentheses in negative numbers: "(12)" for -12.
+ * <p>
+ * <em>User subclasses are not supported.</em> While clients may write
+ * subclasses, such code will not necessarily work and will not be
+ * guaranteed to work stably from release to release.
+ *
+ * @stable ICU 2.0
+ */
+class U_I18N_API NumberFormat : public Format {
+public:
+    /**
+     * Rounding mode.
+     *
+     * <p>
+     * For more detail on rounding modes, see:
+     * http://userguide.icu-project.org/formatparse/numbers/rounding-modes
+     *
+     * @stable ICU 2.4
+     */
+    enum ERoundingMode {
+        kRoundCeiling,  /**< Round towards positive infinity */
+        kRoundFloor,    /**< Round towards negative infinity */
+        kRoundDown,     /**< Round towards zero */
+        kRoundUp,       /**< Round away from zero */
+        kRoundHalfEven, /**< Round towards the nearest integer, or
+                             towards the nearest even integer if equidistant */
+        kRoundHalfDown, /**< Round towards the nearest integer, or
+                             towards zero if equidistant */
+        kRoundHalfUp,   /**< Round towards the nearest integer, or
+                             away from zero if equidistant */
+        /**
+          *  Return U_FORMAT_INEXACT_ERROR if number does not format exactly.
+          *  @stable ICU 4.8
+          */
+        kRoundUnnecessary
+    };
+
+    /**
+     * Alignment Field constants used to construct a FieldPosition object.
+     * Signifies that the position of the integer part or fraction part of
+     * a formatted number should be returned.
+     *
+     * Note: as of ICU 4.4, the values in this enum have been extended to
+     * support identification of all number format fields, not just those
+     * pertaining to alignment.
+     *
+     * These constants are provided for backwards compatibility only.
+     * Please use the C style constants defined in the header file unum.h.
+     *
+     * @see FieldPosition
+     * @stable ICU 2.0
+     */
+    enum EAlignmentFields {
+        /** @stable ICU 2.0 */
+        kIntegerField = UNUM_INTEGER_FIELD,
+        /** @stable ICU 2.0 */
+        kFractionField = UNUM_FRACTION_FIELD,
+        /** @stable ICU 2.0 */
+        kDecimalSeparatorField = UNUM_DECIMAL_SEPARATOR_FIELD,
+        /** @stable ICU 2.0 */
+        kExponentSymbolField = UNUM_EXPONENT_SYMBOL_FIELD,
+        /** @stable ICU 2.0 */
+        kExponentSignField = UNUM_EXPONENT_SIGN_FIELD,
+        /** @stable ICU 2.0 */
+        kExponentField = UNUM_EXPONENT_FIELD,
+        /** @stable ICU 2.0 */
+        kGroupingSeparatorField = UNUM_GROUPING_SEPARATOR_FIELD,
+        /** @stable ICU 2.0 */
+        kCurrencyField = UNUM_CURRENCY_FIELD,
+        /** @stable ICU 2.0 */
+        kPercentField = UNUM_PERCENT_FIELD,
+        /** @stable ICU 2.0 */
+        kPermillField = UNUM_PERMILL_FIELD,
+        /** @stable ICU 2.0 */
+        kSignField = UNUM_SIGN_FIELD,
+        /** @stable ICU 64 */
+        kMeasureUnitField = UNUM_MEASURE_UNIT_FIELD,
+        /** @stable ICU 64 */
+        kCompactField = UNUM_COMPACT_FIELD,
+
+    /**
+     * These constants are provided for backwards compatibility only.
+     * Please use the constants defined in the header file unum.h.
+     */
+        /** @stable ICU 2.0 */
+        INTEGER_FIELD        = UNUM_INTEGER_FIELD,
+        /** @stable ICU 2.0 */
+        FRACTION_FIELD       = UNUM_FRACTION_FIELD
+    };
+
+    /**
+     * Destructor.
+     * @stable ICU 2.0
+     */
+    virtual ~NumberFormat();
+
+    /**
+     * Clones this object polymorphically.
+     * The caller owns the result and should delete it when done.
+     * @return clone, or nullptr if an error occurred
+     * @stable ICU 2.0
+     */
+    virtual NumberFormat* clone() const = 0;
+
+    /**
+     * Return true if the given Format objects are semantically equal.
+     * Objects of different subclasses are considered unequal.
+     * @return    true if the given Format objects are semantically equal.
+     * @stable ICU 2.0
+     */
+    virtual UBool operator==(const Format& other) const;
+
+
+    using Format::format;
+
+    /**
+     * Format an object to produce a string.  This method handles
+     * Formattable objects with numeric types. If the Formattable
+     * object type is not a numeric type, then it returns a failing
+     * UErrorCode.
+     *
+     * @param obj       The object to format.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param pos       On input: an alignment field, if desired.
+     *                  On output: the offsets of the alignment field.
+     * @param status    Output param filled with success/failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.0
+     */
+    virtual UnicodeString& format(const Formattable& obj,
+                                  UnicodeString& appendTo,
+                                  FieldPosition& pos,
+                                  UErrorCode& status) const;
+
+    /**
+     * Format an object to produce a string.  This method handles
+     * Formattable objects with numeric types. If the Formattable
+     * object type is not a numeric type, then it returns a failing
+     * UErrorCode.
+     *
+     * @param obj       The object to format.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param posIter   On return, can be used to iterate over positions
+     *                  of fields generated by this format call.  Can be
+     *                  NULL.
+     * @param status    Output param filled with success/failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString& format(const Formattable& obj,
+                                  UnicodeString& appendTo,
+                                  FieldPositionIterator* posIter,
+                                  UErrorCode& status) const;
+
+    /**
+     * Parse a string to produce an object.  This methods handles
+     * parsing of numeric strings into Formattable objects with numeric
+     * types.
+     * <P>
+     * Before calling, set parse_pos.index to the offset you want to
+     * start parsing at in the source. After calling, parse_pos.index
+     * indicates the position after the successfully parsed text.  If
+     * an error occurs, parse_pos.index is unchanged.
+     * <P>
+     * When parsing, leading whitespace is discarded (with successful
+     * parse), while trailing whitespace is left as is.
+     * <P>
+     * See Format::parseObject() for more.
+     *
+     * @param source    The string to be parsed into an object.
+     * @param result    Formattable to be set to the parse result.
+     *                  If parse fails, return contents are undefined.
+     * @param parse_pos The position to start parsing at. Upon return
+     *                  this param is set to the position after the
+     *                  last character successfully parsed. If the
+     *                  source is not parsed successfully, this param
+     *                  will remain unchanged.
+     * @return          A newly created Formattable* object, or NULL
+     *                  on failure.  The caller owns this and should
+     *                  delete it when done.
+     * @stable ICU 2.0
+     */
+    virtual void parseObject(const UnicodeString& source,
+                             Formattable& result,
+                             ParsePosition& parse_pos) const;
+
+    /**
+     * Format a double number. These methods call the NumberFormat
+     * pure virtual format() methods with the default FieldPosition.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.0
+     */
+    UnicodeString& format(  double number,
+                            UnicodeString& appendTo) const;
+
+    /**
+     * Format a long number. These methods call the NumberFormat
+     * pure virtual format() methods with the default FieldPosition.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.0
+     */
+    UnicodeString& format(  int32_t number,
+                            UnicodeString& appendTo) const;
+
+    /**
+     * Format an int64 number. These methods call the NumberFormat
+     * pure virtual format() methods with the default FieldPosition.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.8
+     */
+    UnicodeString& format(  int64_t number,
+                            UnicodeString& appendTo) const;
+
+    /**
+     * Format a double number. Concrete subclasses must implement
+     * these pure virtual methods.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param pos       On input: an alignment field, if desired.
+     *                  On output: the offsets of the alignment field.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.0
+     */
+    virtual UnicodeString& format(double number,
+                                  UnicodeString& appendTo,
+                                  FieldPosition& pos) const = 0;
+    /**
+     * Format a double number. By default, the parent function simply
+     * calls the base class and does not return an error status.
+     * Therefore, the status may be ignored in some subclasses.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param pos       On input: an alignment field, if desired.
+     *                  On output: the offsets of the alignment field.
+     * @param status    error status
+     * @return          Reference to 'appendTo' parameter.
+     * @internal
+     */
+    virtual UnicodeString& format(double number,
+                                  UnicodeString& appendTo,
+                                  FieldPosition& pos,
+                                  UErrorCode &status) const;
+    /**
+     * Format a double number. Subclasses must implement
+     * this method.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param posIter   On return, can be used to iterate over positions
+     *                  of fields generated by this format call.
+     *                  Can be NULL.
+     * @param status    Output param filled with success/failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString& format(double number,
+                                  UnicodeString& appendTo,
+                                  FieldPositionIterator* posIter,
+                                  UErrorCode& status) const;
+    /**
+     * Format a long number. Concrete subclasses must implement
+     * these pure virtual methods.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param pos       On input: an alignment field, if desired.
+     *                  On output: the offsets of the alignment field.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.0
+    */
+    virtual UnicodeString& format(int32_t number,
+                                  UnicodeString& appendTo,
+                                  FieldPosition& pos) const = 0;
+
+    /**
+     * Format a long number. Concrete subclasses may override
+     * this function to provide status return.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param pos       On input: an alignment field, if desired.
+     *                  On output: the offsets of the alignment field.
+     * @param status the output status.
+     * @return          Reference to 'appendTo' parameter.
+     * @internal
+    */
+    virtual UnicodeString& format(int32_t number,
+                                  UnicodeString& appendTo,
+                                  FieldPosition& pos,
+                                  UErrorCode &status) const;
+
+    /**
+     * Format an int32 number. Subclasses must implement
+     * this method.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param posIter   On return, can be used to iterate over positions
+     *                  of fields generated by this format call.
+     *                  Can be NULL.
+     * @param status    Output param filled with success/failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString& format(int32_t number,
+                                  UnicodeString& appendTo,
+                                  FieldPositionIterator* posIter,
+                                  UErrorCode& status) const;
+    /**
+     * Format an int64 number. (Not abstract to retain compatibility
+     * with earlier releases, however subclasses should override this
+     * method as it just delegates to format(int32_t number...);
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param pos       On input: an alignment field, if desired.
+     *                  On output: the offsets of the alignment field.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 2.8
+    */
+    virtual UnicodeString& format(int64_t number,
+                                  UnicodeString& appendTo,
+                                  FieldPosition& pos) const;
+
+    /**
+     * Format an int64 number. (Not abstract to retain compatibility
+     * with earlier releases, however subclasses should override this
+     * method as it just delegates to format(int32_t number...);
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param pos       On input: an alignment field, if desired.
+     *                  On output: the offsets of the alignment field.
+     * @param status    Output param filled with success/failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @internal
+    */
+    virtual UnicodeString& format(int64_t number,
+                                  UnicodeString& appendTo,
+                                  FieldPosition& pos,
+                                  UErrorCode& status) const;
+    /**
+     * Format an int64 number. Subclasses must implement
+     * this method.
+     *
+     * @param number    The value to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param posIter   On return, can be used to iterate over positions
+     *                  of fields generated by this format call.
+     *                  Can be NULL.
+     * @param status    Output param filled with success/failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString& format(int64_t number,
+                                  UnicodeString& appendTo,
+                                  FieldPositionIterator* posIter,
+                                  UErrorCode& status) const;
+
+    /**
+     * Format a decimal number. Subclasses must implement
+     * this method.  The syntax of the unformatted number is a "numeric string"
+     * as defined in the Decimal Arithmetic Specification, available at
+     * http://speleotrove.com/decimal
+     *
+     * @param number    The unformatted number, as a string, to be formatted.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param posIter   On return, can be used to iterate over positions
+     *                  of fields generated by this format call.
+     *                  Can be NULL.
+     * @param status    Output param filled with success/failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @stable ICU 4.4
+     */
+    virtual UnicodeString& format(StringPiece number,
+                                  UnicodeString& appendTo,
+                                  FieldPositionIterator* posIter,
+                                  UErrorCode& status) const;
+
+// Can't use #ifndef U_HIDE_INTERNAL_API because these are virtual methods
+
+    /**
+     * Format a decimal number.
+     * The number is a DecimalQuantity wrapper onto a floating point decimal number.
+     * The default implementation in NumberFormat converts the decimal number
+     * to a double and formats that.  Subclasses of NumberFormat that want
+     * to specifically handle big decimal numbers must override this method.
+     * class DecimalFormat does so.
+     *
+     * @param number    The number, a DecimalQuantity format Decimal Floating Point.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param posIter   On return, can be used to iterate over positions
+     *                  of fields generated by this format call.
+     * @param status    Output param filled with success/failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @internal
+     */
+    virtual UnicodeString& format(const number::impl::DecimalQuantity &number,
+                                  UnicodeString& appendTo,
+                                  FieldPositionIterator* posIter,
+                                  UErrorCode& status) const;
+
+    /**
+     * Format a decimal number.
+     * The number is a DecimalQuantity wrapper onto a floating point decimal number.
+     * The default implementation in NumberFormat converts the decimal number
+     * to a double and formats that.  Subclasses of NumberFormat that want
+     * to specifically handle big decimal numbers must override this method.
+     * class DecimalFormat does so.
+     *
+     * @param number    The number, a DecimalQuantity format Decimal Floating Point.
+     * @param appendTo  Output parameter to receive result.
+     *                  Result is appended to existing contents.
+     * @param pos       On input: an alignment field, if desired.
+     *                  On output: the offsets of the alignment field.
+     * @param status    Output param filled with success/failure status.
+     * @return          Reference to 'appendTo' parameter.
+     * @internal
+     */
+    virtual UnicodeString& format(const number::impl::DecimalQuantity &number,
+                                  UnicodeString& appendTo,
+                                  FieldPosition& pos,
+                                  UErrorCode& status) const;
+
+   /**
+    * Return a long if possible (e.g. within range LONG_MAX,
+    * LONG_MAX], and with no decimals), otherwise a double.  If
+    * IntegerOnly is set, will stop at a decimal point (or equivalent;
+    * e.g. for rational numbers "1 2/3", will stop after the 1).
+    * <P>
+    * If no object can be parsed, index is unchanged, and NULL is
+    * returned.
+    * <P>
+    * This is a pure virtual which concrete subclasses must implement.
+    *
+    * @param text           The text to be parsed.
+    * @param result         Formattable to be set to the parse result.
+    *                       If parse fails, return contents are undefined.
+    * @param parsePosition  The position to start parsing at on input.
+    *                       On output, moved to after the last successfully
+    *                       parse character. On parse failure, does not change.
+    * @stable ICU 2.0
+    */
+    virtual void parse(const UnicodeString& text,
+                       Formattable& result,
+                       ParsePosition& parsePosition) const = 0;
+
+    /**
+     * Parse a string as a numeric value, and return a Formattable
+     * numeric object. This method parses integers only if IntegerOnly
+     * is set.
+     *
+     * @param text          The text to be parsed.
+     * @param result        Formattable to be set to the parse result.
+     *                      If parse fails, return contents are undefined.
+     * @param status        Output parameter set to a failure error code
+     *                      when a failure occurs. The error code when the
+     *                      string fails to parse is U_INVALID_FORMAT_ERROR,
+     *                      unless overridden by a subclass.
+     * @see                 NumberFormat::isParseIntegerOnly
+     * @stable ICU 2.0
+     */
+    virtual void parse(const UnicodeString& text,
+                       Formattable& result,
+                       UErrorCode& status) const;
+
+    /**
+     * Parses text from the given string as a currency amount.  Unlike
+     * the parse() method, this method will attempt to parse a generic
+     * currency name, searching for a match of this object's locale's
+     * currency display names, or for a 3-letter ISO currency code.
+     * This method will fail if this format is not a currency format,
+     * that is, if it does not contain the currency pattern symbol
+     * (U+00A4) in its prefix or suffix.
+     *
+     * @param text the string to parse
+     * @param pos  input-output position; on input, the position within text
+     *             to match; must have 0 <= pos.getIndex() < text.length();
+     *             on output, the position after the last matched character.
+     *             If the parse fails, the position in unchanged upon output.
+     * @return     if parse succeeds, a pointer to a newly-created CurrencyAmount
+     *             object (owned by the caller) containing information about
+     *             the parsed currency; if parse fails, this is NULL.
+     * @stable ICU 49
+     */
+    virtual CurrencyAmount* parseCurrency(const UnicodeString& text,
+                                          ParsePosition& pos) const;
+
+    /**
+     * Return true if this format will parse numbers as integers
+     * only.  For example in the English locale, with ParseIntegerOnly
+     * true, the string "1234." would be parsed as the integer value
+     * 1234 and parsing would stop at the "." character.  Of course,
+     * the exact format accepted by the parse operation is locale
+     * dependant and determined by sub-classes of NumberFormat.
+     * @return    true if this format will parse numbers as integers
+     *            only.
+     * @stable ICU 2.0
+     */
+    UBool isParseIntegerOnly(void) const;
+
+    /**
+     * Sets whether or not numbers should be parsed as integers only.
+     * @param value    set True, this format will parse numbers as integers
+     *                 only.
+     * @see isParseIntegerOnly
+     * @stable ICU 2.0
+     */
+    virtual void setParseIntegerOnly(UBool value);
+
+    /**
+     * Sets whether lenient parsing should be enabled (it is off by default).
+     *
+     * @param enable \c TRUE if lenient parsing should be used,
+     *               \c FALSE otherwise.
+     * @stable ICU 4.8
+     */
+    virtual void setLenient(UBool enable);
+
+    /**
+     * Returns whether lenient parsing is enabled (it is off by default).
+     *
+     * @return \c TRUE if lenient parsing is enabled,
+     *         \c FALSE otherwise.
+     * @see #setLenient
+     * @stable ICU 4.8
+     */
+    virtual UBool isLenient(void) const;
+
+    /**
+     * Create a default style NumberFormat for the current default locale.
+     * The default formatting style is locale dependent.
+     * <p>
+     * <strong>NOTE:</strong> New users are strongly encouraged to use
+     * {@link icu::number::NumberFormatter} instead of NumberFormat.
+     * @stable ICU 2.0
+     */
+    static NumberFormat* U_EXPORT2 createInstance(UErrorCode&);
+
+    /**
+     * Create a default style NumberFormat for the specified locale.
+     * The default formatting style is locale dependent.
+     * @param inLocale    the given locale.
+     * <p>
+     * <strong>NOTE:</strong> New users are strongly encouraged to use
+     * {@link icu::number::NumberFormatter} instead of NumberFormat.
+     * @stable ICU 2.0
+     */
+    static NumberFormat* U_EXPORT2 createInstance(const Locale& inLocale,
+                                        UErrorCode&);
+
+    /**
+     * Create a specific style NumberFormat for the specified locale.
+     * <p>
+     * <strong>NOTE:</strong> New users are strongly encouraged to use
+     * {@link icu::number::NumberFormatter} instead of NumberFormat.
+     * @param desiredLocale    the given locale.
+     * @param style            the given style.
+     * @param errorCode        Output param filled with success/failure status.
+     * @return                 A new NumberFormat instance.
+     * @stable ICU 4.8
+     */
+    static NumberFormat* U_EXPORT2 createInstance(const Locale& desiredLocale,
+                                                  UNumberFormatStyle style,
+                                                  UErrorCode& errorCode);
+
+#ifndef U_HIDE_INTERNAL_API
+
+    /**
+     * ICU use only.
+     * Creates NumberFormat instance without using the cache.
+     * @internal
+     */
+    static NumberFormat* internalCreateInstance(
+            const Locale& desiredLocale,
+            UNumberFormatStyle style,
+            UErrorCode& errorCode);
+
+    /**
+     * ICU use only.
+     * Returns handle to the shared, cached NumberFormat instance for given
+     * locale. On success, caller must call removeRef() on returned value
+     * once it is done with the shared instance.
+     * @internal
+     */
+    static const SharedNumberFormat* U_EXPORT2 createSharedInstance(
+            const Locale& inLocale, UNumberFormatStyle style, UErrorCode& status);
+
+#endif  /* U_HIDE_INTERNAL_API */
+
+    /**
+     * Returns a currency format for the current default locale.
+     * <p>
+     * <strong>NOTE:</strong> New users are strongly encouraged to use
+     * {@link icu::number::NumberFormatter} instead of NumberFormat.
+     * @stable ICU 2.0
+     */
+    static NumberFormat* U_EXPORT2 createCurrencyInstance(UErrorCode&);
+
+    /**
+     * Returns a currency format for the specified locale.
+     * <p>
+     * <strong>NOTE:</strong> New users are strongly encouraged to use
+     * {@link icu::number::NumberFormatter} instead of NumberFormat.
+     * @param inLocale    the given locale.
+     * @stable ICU 2.0
+     */
+    static NumberFormat* U_EXPORT2 createCurrencyInstance(const Locale& inLocale,
+                                                UErrorCode&);
+
+    /**
+     * Returns a percentage format for the current default locale.
+     * <p>
+     * <strong>NOTE:</strong> New users are strongly encouraged to use
+     * {@link icu::number::NumberFormatter} instead of NumberFormat.
+     * @stable ICU 2.0
+     */
+    static NumberFormat* U_EXPORT2 createPercentInstance(UErrorCode&);
+
+    /**
+     * Returns a percentage format for the specified locale.
+     * <p>
+     * <strong>NOTE:</strong> New users are strongly encouraged to use
+     * {@link icu::number::NumberFormatter} instead of NumberFormat.
+     * @param inLocale    the given locale.
+     * @stable ICU 2.0
+     */
+    static NumberFormat* U_EXPORT2 createPercentInstance(const Locale& inLocale,
+                                               UErrorCode&);
+
+    /**
+     * Returns a scientific format for the current default locale.
+     * <p>
+     * <strong>NOTE:</strong> New users are strongly encouraged to use
+     * {@link icu::number::NumberFormatter} instead of NumberFormat.
+     * @stable ICU 2.0
+     */
+    static NumberFormat* U_EXPORT2 createScientificInstance(UErrorCode&);
+
+    /**
+     * Returns a scientific format for the specified locale.
+     * <p>
+     * <strong>NOTE:</strong> New users are strongly encouraged to use
+     * {@link icu::number::NumberFormatter} instead of NumberFormat.
+     * @param inLocale    the given locale.
+     * @stable ICU 2.0
+     */
+    static NumberFormat* U_EXPORT2 createScientificInstance(const Locale& inLocale,
+                                                UErrorCode&);
+
+    /**
+     * Get the set of Locales for which NumberFormats are installed.
+     * @param count    Output param to receive the size of the locales
+     * @stable ICU 2.0
+     */
+    static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
+
+#if !UCONFIG_NO_SERVICE
+    /**
+     * Register a new NumberFormatFactory.  The factory will be adopted.
+     * Because ICU may choose to cache NumberFormat objects internally,
+     * this must be called at application startup, prior to any calls to
+     * NumberFormat::createInstance to avoid undefined behavior.
+     * @param toAdopt the NumberFormatFactory instance to be adopted
+     * @param status the in/out status code, no special meanings are assigned
+     * @return a registry key that can be used to unregister this factory
+     * @stable ICU 2.6
+     */
+    static URegistryKey U_EXPORT2 registerFactory(NumberFormatFactory* toAdopt, UErrorCode& status);
+
+    /**
+     * Unregister a previously-registered NumberFormatFactory using the key returned from the
+     * register call.  Key becomes invalid after a successful call and should not be used again.
+     * The NumberFormatFactory corresponding to the key will be deleted.
+     * Because ICU may choose to cache NumberFormat objects internally,
+     * this should be called during application shutdown, after all calls to
+     * NumberFormat::createInstance to avoid undefined behavior.
+     * @param key the registry key returned by a previous call to registerFactory
+     * @param status the in/out status code, no special meanings are assigned
+     * @return TRUE if the factory for the key was successfully unregistered
+     * @stable ICU 2.6
+     */
+    static UBool U_EXPORT2 unregister(URegistryKey key, UErrorCode& status);
+
+    /**
+     * Return a StringEnumeration over the locales available at the time of the call,
+     * including registered locales.
+     * @return a StringEnumeration over the locales available at the time of the call
+     * @stable ICU 2.6
+     */
+    static StringEnumeration* U_EXPORT2 getAvailableLocales(void);
+#endif /* UCONFIG_NO_SERVICE */
+
+    /**
+     * Returns true if grouping is used in this format. For example,
+     * in the English locale, with grouping on, the number 1234567
+     * might be formatted as "1,234,567". The grouping separator as
+     * well as the size of each group is locale dependent and is
+     * determined by sub-classes of NumberFormat.
+     * @see setGroupingUsed
+     * @stable ICU 2.0
+     */
+    UBool isGroupingUsed(void) const;
+
+    /**
+     * Set whether or not grouping will be used in this format.
+     * @param newValue    True, grouping will be used in this format.
+     * @see getGroupingUsed
+     * @stable ICU 2.0
+     */
+    virtual void setGroupingUsed(UBool newValue);
+
+    /**
+     * Returns the maximum number of digits allowed in the integer portion of a
+     * number.
+     * @return     the maximum number of digits allowed in the integer portion of a
+     *             number.
+     * @see setMaximumIntegerDigits
+     * @stable ICU 2.0
+     */
+    int32_t getMaximumIntegerDigits(void) const;
+
+    /**
+     * Sets the maximum number of digits allowed in the integer portion of a
+     * number. maximumIntegerDigits must be >= minimumIntegerDigits.  If the
+     * new value for maximumIntegerDigits is less than the current value
+     * of minimumIntegerDigits, then minimumIntegerDigits will also be set to
+     * the new value.
+     *
+     * @param newValue    the new value for the maximum number of digits
+     *                    allowed in the integer portion of a number.
+     * @see getMaximumIntegerDigits
+     * @stable ICU 2.0
+     */
+    virtual void setMaximumIntegerDigits(int32_t newValue);
+
+    /**
+     * Returns the minimum number of digits allowed in the integer portion of a
+     * number.
+     * @return    the minimum number of digits allowed in the integer portion of a
+     *            number.
+     * @see setMinimumIntegerDigits
+     * @stable ICU 2.0
+     */
+    int32_t getMinimumIntegerDigits(void) const;
+
+    /**
+     * Sets the minimum number of digits allowed in the integer portion of a
+     * number. minimumIntegerDigits must be &lt;= maximumIntegerDigits.  If the
+     * new value for minimumIntegerDigits exceeds the current value
+     * of maximumIntegerDigits, then maximumIntegerDigits will also be set to
+     * the new value.
+     * @param newValue    the new value to be set.
+     * @see getMinimumIntegerDigits
+     * @stable ICU 2.0
+     */
+    virtual void setMinimumIntegerDigits(int32_t newValue);
+
+    /**
+     * Returns the maximum number of digits allowed in the fraction portion of a
+     * number.
+     * @return    the maximum number of digits allowed in the fraction portion of a
+     *            number.
+     * @see setMaximumFractionDigits
+     * @stable ICU 2.0
+     */
+    int32_t getMaximumFractionDigits(void) const;
+
+    /**
+     * Sets the maximum number of digits allowed in the fraction portion of a
+     * number. maximumFractionDigits must be >= minimumFractionDigits.  If the
+     * new value for maximumFractionDigits is less than the current value
+     * of minimumFractionDigits, then minimumFractionDigits will also be set to
+     * the new value.
+     * @param newValue    the new value to be set.
+     * @see getMaximumFractionDigits
+     * @stable ICU 2.0
+     */
+    virtual void setMaximumFractionDigits(int32_t newValue);
+
+    /**
+     * Returns the minimum number of digits allowed in the fraction portion of a
+     * number.
+     * @return    the minimum number of digits allowed in the fraction portion of a
+     *            number.
+     * @see setMinimumFractionDigits
+     * @stable ICU 2.0
+     */
+    int32_t getMinimumFractionDigits(void) const;
+
+    /**
+     * Sets the minimum number of digits allowed in the fraction portion of a
+     * number. minimumFractionDigits must be &lt;= maximumFractionDigits.   If the
+     * new value for minimumFractionDigits exceeds the current value
+     * of maximumFractionDigits, then maximumIntegerDigits will also be set to
+     * the new value
+     * @param newValue    the new value to be set.
+     * @see getMinimumFractionDigits
+     * @stable ICU 2.0
+     */
+    virtual void setMinimumFractionDigits(int32_t newValue);
+
+    /**
+     * Sets the currency used to display currency
+     * amounts.  This takes effect immediately, if this format is a
+     * currency format.  If this format is not a currency format, then
+     * the currency is used if and when this object becomes a
+     * currency format.
+     * @param theCurrency a 3-letter ISO code indicating new currency
+     * to use.  It need not be null-terminated.  May be the empty
+     * string or NULL to indicate no currency.
+     * @param ec input-output error code
+     * @stable ICU 3.0
+     */
+    virtual void setCurrency(const char16_t* theCurrency, UErrorCode& ec);
+
+    /**
+     * Gets the currency used to display currency
+     * amounts.  This may be an empty string for some subclasses.
+     * @return a 3-letter null-terminated ISO code indicating
+     * the currency in use, or a pointer to the empty string.
+     * @stable ICU 2.6
+     */
+    const char16_t* getCurrency() const;
+
+    /**
+     * Set a particular UDisplayContext value in the formatter, such as
+     * UDISPCTX_CAPITALIZATION_FOR_STANDALONE.
+     * @param value The UDisplayContext value to set.
+     * @param status Input/output status. If at entry this indicates a failure
+     *               status, the function will do nothing; otherwise this will be
+     *               updated with any new status from the function.
+     * @stable ICU 53
+     */
+    virtual void setContext(UDisplayContext value, UErrorCode& status);
+
+    /**
+     * Get the formatter's UDisplayContext value for the specified UDisplayContextType,
+     * such as UDISPCTX_TYPE_CAPITALIZATION.
+     * @param type The UDisplayContextType whose value to return
+     * @param status Input/output status. If at entry this indicates a failure
+     *               status, the function will do nothing; otherwise this will be
+     *               updated with any new status from the function.
+     * @return The UDisplayContextValue for the specified type.
+     * @stable ICU 53
+     */
+    virtual UDisplayContext getContext(UDisplayContextType type, UErrorCode& status) const;
+
+    /**
+     * Get the rounding mode. This will always return NumberFormat::ERoundingMode::kRoundUnnecessary
+     * if the subclass does not support rounding. 
+     * @return A rounding mode
+     * @stable ICU 60
+     */
+    virtual ERoundingMode getRoundingMode(void) const;
+
+    /**
+     * Set the rounding mode. If a subclass does not support rounding, this will do nothing.
+     * @param roundingMode A rounding mode
+     * @stable ICU 60
+     */
+    virtual void setRoundingMode(ERoundingMode roundingMode);
+
+public:
+
+    /**
+     * Return the class ID for this class.  This is useful for
+     * comparing to a return value from getDynamicClassID(). Note that,
+     * because NumberFormat is an abstract base class, no fully constructed object
+     * will have the class ID returned by NumberFormat::getStaticClassID().
+     * @return The class ID for all objects of this class.
+     * @stable ICU 2.0
+     */
+    static UClassID U_EXPORT2 getStaticClassID(void);
+
+    /**
+     * Returns a unique class ID POLYMORPHICALLY.  Pure virtual override.
+     * This method is to implement a simple version of RTTI, since not all
+     * C++ compilers support genuine RTTI.  Polymorphic operator==() and
+     * clone() methods call this method.
+     * <P>
+     * @return The class ID for this object. All objects of a
+     * given class have the same class ID.  Objects of
+     * other classes have different class IDs.
+     * @stable ICU 2.0
+     */
+    virtual UClassID getDynamicClassID(void) const = 0;
+
+protected:
+
+    /**
+     * Default constructor for subclass use only.
+     * @stable ICU 2.0
+     */
+    NumberFormat();
+
+    /**
+     * Copy constructor.
+     * @stable ICU 2.0
+     */
+    NumberFormat(const NumberFormat&);
+
+    /**
+     * Assignment operator.
+     * @stable ICU 2.0
+     */
+    NumberFormat& operator=(const NumberFormat&);
+
+    /**
+     * Returns the currency in effect for this formatter.  Subclasses
+     * should override this method as needed.  Unlike getCurrency(),
+     * this method should never return "".
+     * @result output parameter for null-terminated result, which must
+     * have a capacity of at least 4
+     * @internal
+     */
+    virtual void getEffectiveCurrency(char16_t* result, UErrorCode& ec) const;
+
+#ifndef U_HIDE_INTERNAL_API
+    /**
+     * Creates the specified number format style of the desired locale.
+     * If mustBeDecimalFormat is TRUE, then the returned pointer is
+     * either a DecimalFormat or it is NULL.
+     * @internal
+     */
+    static NumberFormat* makeInstance(const Locale& desiredLocale,
+                                      UNumberFormatStyle style,
+                                      UBool mustBeDecimalFormat,
+                                      UErrorCode& errorCode);
+#endif  /* U_HIDE_INTERNAL_API */
+
+private:
+
+    static UBool isStyleSupported(UNumberFormatStyle style);
+
+    /**
+     * Creates the specified decimal format style of the desired locale.
+     * @param desiredLocale    the given locale.
+     * @param style            the given style.
+     * @param errorCode        Output param filled with success/failure status.
+     * @return                 A new NumberFormat instance.
+     */
+    static NumberFormat* makeInstance(const Locale& desiredLocale,
+                                      UNumberFormatStyle style,
+                                      UErrorCode& errorCode);
+
+    UBool       fGroupingUsed;
+    int32_t     fMaxIntegerDigits;
+    int32_t     fMinIntegerDigits;
+    int32_t     fMaxFractionDigits;
+    int32_t     fMinFractionDigits;
+
+  protected:
+    /** \internal */
+    static const int32_t gDefaultMaxIntegerDigits;
+    /** \internal */
+    static const int32_t gDefaultMinIntegerDigits;
+
+  private:
+    UBool      fParseIntegerOnly;
+    UBool      fLenient; // TRUE => lenient parse is enabled
+
+    // ISO currency code
+    char16_t      fCurrency[4];
+
+    UDisplayContext fCapitalizationContext;
+
+    friend class ICUNumberFormatFactory; // access to makeInstance
+    friend class ICUNumberFormatService;
+    friend class ::NumberFormatTest;  // access to isStyleSupported()
+};
+
+#if !UCONFIG_NO_SERVICE
+/**
+ * A NumberFormatFactory is used to register new number formats.  The factory
+ * should be able to create any of the predefined formats for each locale it
+ * supports.  When registered, the locales it supports extend or override the
+ * locale already supported by ICU.
+ *
+ * @stable ICU 2.6
+ */
+class U_I18N_API NumberFormatFactory : public UObject {
+public:
+
+    /**
+     * Destructor
+     * @stable ICU 3.0
+     */
+    virtual ~NumberFormatFactory();
+
+    /**
+     * Return true if this factory will be visible.  Default is true.
+     * If not visible, the locales supported by this factory will not
+     * be listed by getAvailableLocales.
+     * @stable ICU 2.6
+     */
+    virtual UBool visible(void) const = 0;
+
+    /**
+     * Return the locale names directly supported by this factory.  The number of names
+     * is returned in count;
+     * @stable ICU 2.6
+     */
+    virtual const UnicodeString * getSupportedIDs(int32_t &count, UErrorCode& status) const = 0;
+
+    /**
+     * Return a number format of the appropriate type.  If the locale
+     * is not supported, return null.  If the locale is supported, but
+     * the type is not provided by this service, return null.  Otherwise
+     * return an appropriate instance of NumberFormat.
+     * @stable ICU 2.6
+     */
+    virtual NumberFormat* createFormat(const Locale& loc, UNumberFormatStyle formatType) = 0;
+};
+
+/**
+ * A NumberFormatFactory that supports a single locale.  It can be visible or invisible.
+ * @stable ICU 2.6
+ */
+class U_I18N_API SimpleNumberFormatFactory : public NumberFormatFactory {
+protected:
+    /**
+     * True if the locale supported by this factory is visible.
+     * @stable ICU 2.6
+     */
+    const UBool _visible;
+
+    /**
+     * The locale supported by this factory, as a UnicodeString.
+     * @stable ICU 2.6
+     */
+    UnicodeString _id;
+
+public:
+    /**
+     * @stable ICU 2.6
+     */
+    SimpleNumberFormatFactory(const Locale& locale, UBool visible = TRUE);
+
+    /**
+     * @stable ICU 3.0
+     */
+    virtual ~SimpleNumberFormatFactory();
+
+    /**
+     * @stable ICU 2.6
+     */
+    virtual UBool visible(void) const;
+
+    /**
+     * @stable ICU 2.6
+     */
+    virtual const UnicodeString * getSupportedIDs(int32_t &count, UErrorCode& status) const;
+};
+#endif /* #if !UCONFIG_NO_SERVICE */
+
+// -------------------------------------
+
+inline UBool
+NumberFormat::isParseIntegerOnly() const
+{
+    return fParseIntegerOnly;
+}
+
+inline UBool
+NumberFormat::isLenient() const
+{
+    return fLenient;
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_FORMATTING */
+
+#endif /* U_SHOW_CPLUSPLUS_API */
+
+#endif // _NUMFMT
+//eof