www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.bugs - [Issue 9462] New: Delegate breaks immutability

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=9462

           Summary: Delegate breaks immutability
           Product: D
           Version: D2
          Platform: All
        OS/Version: All
            Status: NEW
          Keywords: accepts-invalid
          Severity: major
          Priority: P2
         Component: DMD
        AssignedTo: nobody puremagic.com
        ReportedBy: maxim maxim-fomin.ru


--- Comment #0 from Maxim Fomin <maxim maxim-fomin.ru> 2013-02-06 12:39:37 PST
---
This should not work, since alternative ways of doing so (including manual
creation of delegate object and initialization of .ptr and .funcptr properties
is rejected) are banned.

import std.stdio;

struct S
{
    int i;
    void bar()
    {
        ++i;
    }
    void foo() immutable
    {
        //bar(); //error   
        (&bar)(); //works, lang hole
    }
}

void main()
{
    immutable S s;
    writeln(s.i);
    s.foo();
    writeln(s.i);
}

dmd is smart enough to avoid delegate allocation, it just issues call directly
to bar()

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
Feb 06 2013
parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=9462



--- Comment #1 from Maxim Fomin <maxim maxim-fomin.ru> 2013-02-06 12:55:41 PST
---
Forgot to mention:  

void delegate() dg = &bar;
dg(); 

also is accepted.

-- 
Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
Feb 06 2013