[Issue 7866] New: Type printing too for single nulls

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=7866

           Summary: Type printing too for single nulls
           Product: D
           Version: D2
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: enhancement
          Priority: P2
         Component: Phobos
        AssignedTo: nobody at puremagic.com
        ReportedBy: bearophile_hugs at eml.cc


--- Comment #0 from bearophile_hugs at eml.cc 2012-04-08 17:23:23 PDT ---
D2 code:

import std.stdio;
class Foo {}
void main() {
    Foo[] bar = [null, new Foo];
    foreach (f; bar)
        writeln(f);
}


Output, DMD 2.059beta3:

null
test.Foo


But the first null is a Foo class empty reference, it's not just a null. So I'd
like writeln to print more information about the type of the null, with an
output like this:

cast(Foo)null
test.Foo

Or:

cast(test.Foo)null
test.Foo


If you want similar output is useful for structs too:

import std.stdio;
struct Foo {}
void main() {
    Foo* f;
    writeln(f);
}


Currently prints:

null


But a better and more informative output may be:

cast(Foo*)null

Or:

cast(test.Foo*)null


Inside collections probably "null" is enough still, to avoid a too much long
output:

import std.stdio;
struct Foo {}
void main() {
    Foo*[] a = [null, null];
    writeln(a);
}


Current output, acceptable:

[null, null]

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------