| Subject | Re: [firebird-support] Is this a bug of Firebird? |
|---|---|
| Author | DougC |
| Post date | 2017-02-09T13:17:26Z |
Delphi's latest compiler provides a hint in these cases:
var
x: Int32;
begin
try
x := 0;
x := 1;
writeln(x);
end.
[dcc32 Hint] Project1.dpr(14): H2077 Value assigned to 'x' never used
(Line 14 is the one assigning zero.)
---- On Thu, 09 Feb 2017 04:30:06 -0500 Tim Ward tdw@... [firebird-support] <firebird-support@yahoogroups.com> wrote ----
It' the equivalent in a conventional programming language of saying:x = a;x = b;where the compiler is expected to know that neither a not the first assignment have any side effects other than the assignment (and where the expression b doesn't depend on the value of x)(and where x isn't volatile, ect ect).A compiler *could* detect and warn about such things (ie it's not forbidden by the laws of mathematics) but I don't think I know of any that do. And as there are good reasons for deliberately wanting to do the above it could only be a warning, not an error.