Re: Ada or C++ acting 'correctly' here?

[Florian Weimer <fw@cygnus.stuttgart.netsurf.de>]

bill@mooner writes:

> ----------------------------
> #include <iostream>
> int main()
> {
>   cout<<(500000000*7);
>   return 0;
> }
> -----------------------------

Quotation from ISO/IEC 14882:1998(E), Chapter 5 (Expressions):

|  5 If during the evaluation of an expression, the result is not
|    mathematically defined or not in the range of representable values
|    for its type, the behavior is undefined, unless such an expression is
|    a constant expression (5.19), in which case the program is ill-formed.

The standard doesn't mention that no diagnonstic is required, so
conforming implementations have to refuse to compile this program.

> ----------------------------
> with Ada.Integer_Text_Io; use Ada.Integer_Text_Io;
> procedure Test_Multi is
>   begin
>    Put( 500000000*7 );
>   end Test_Multi;
> -----------------------------

Quotation from ISO/IEC 8652:1995(E), Section 4.9 (Static Expressions
and Static Subtypes):

| 33 A static expression is evaluated at compile time except when it is
|    part of the right operand of a static short-circuit control form whose
|    value is determined by its left operand.  This evaluation is performed
|    exactly, without performing Overflow_Checks.  For a static expression
|    that is evaluated:
|     
|        34  The expression is illegal if its evaluation fails a
|            language-defined check other than Overflow_Check.

Again, conforming compilers must refuse to compile this program.

(BTW: It's pretty pointless to compare languages this way, isn't it?)