Name: ngR10089 Date: 02/11/2004



The latest spec "Autoboxing and Auto-Unboxing support for the Javatm
Programming Language" says about the type of the prefix/postfix
decrement/increment expressions:

JLS 15.14.1 Postfix Increment Operator ++
  "The type of the postfix increment expression is the type of the variable "
JLS 15.14.2 Postfix Decrement Operator --
  "The type of the postfix decrement expression is the type of the variable."
JLS 15.15.1 Prefix Increment Operator ++
  "The type of the prefix increment expression is the type of the variable."
JLS 15.15.2 Prefix Decrement Operator --
  "The type of the prefix decrement expression is the type of the variable."
 
javac (jdk1.5.0-b37) successfully compiles test below.

The test execution shows that the type of the prefix/postfix
decrement/increment expressions is not the type of the variable.

> java -version
java version "1.5.0-beta2"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-beta2-b37)
Java HotSpot(TM) Client VM (build 1.5.0-beta2-b37, mixed mode)

> javac -d . -source 1.5 test.java
> java -Xfuture p.test

Character 2 12
Byte 0 10
Short 1 11
Integer 3 13
Long 4 14
Float 5 15
Double 6 16

>
----------------- test.java -----------------
package p;

public class test {

    static final int byte_t = 0;
    static final int short_t = 1;
    static final int char_t = 2;
    static final int int_t = 3;
    static final int long_t = 4;
    static final int float_t = 5;
    static final int double_t = 6;
    static final int Byte_t = 10;
    static final int Short_t = 11;
    static final int Character_t = 12;
    static final int Integer_t = 13;
    static final int Long_t = 14;
    static final int Float_t = 15;
    static final int Double_t = 16;

    static int getType(byte b) {
        return byte_t;
    }
    static int getType(short s) {
        return short_t;
    }
    static int getType(char c) {
        return char_t;
    }
    static int getType(int i) {
        return int_t;
    }
    static int getType(long l) {
        return long_t;
    }
    static int getType(float f) {
        return float_t;
    }
    static int getType(double d) {
        return double_t;
    }
    static int getType(Byte b) {
        return Byte_t;
    }
    static int getType(Short s) {
        return Short_t;
    }
    static int getType(Character c) {
        return Character_t;
    }
    static int getType(Integer i) {
        return Integer_t;
    }
    static int getType(Long l) {
        return Long_t;
    }
    static int getType(Float f) {
        return Float_t;
    }
    static int getType(Double d) {
        return Double_t;
    }

    public static void main(String argv[]) {
        Character c1 = new Character((char)2);
        Byte b1 = new Byte((byte)3);
        Short s1 = new Short((short)4);
        Integer i1 = new Integer(5);
        Long l1 = new Long(6);
        Float f1 = new Float(7);
        Double d1 = new Double(8);

        System.out.println("Character "+getType(c1++)+" "+getType(c1));
        System.out.println("Byte "+getType(b1--)+" "+getType(b1));
        System.out.println("Short "+getType(++s1)+" "+getType(s1));
        System.out.println("Integer "+getType(--i1)+" "+getType(i1));
        System.out.println("Long "+getType(l1++)+" "+getType(l1));
        System.out.println("Float "+getType(f1--)+" "+getType(f1));
        System.out.println("Double "+getType(++d1)+" "+getType(d1));
    }
}
---------------------------------------------

The JCK tests
  lang/EXPR/expr182/expr18208/expr18208.html
  lang/EXPR/expr190/expr19008/expr19008.html
  lang/EXPR/expr205/expr20510/expr20510.html
  lang/EXPR/expr213/expr21308/expr21308.html
fail due to this bug.

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