http://d.puremagic.com/issues/show_bug.cgi?id=5165

           Summary: compiler add a cast and then complain that the cast
                    have no effect, giving no .o file
           Product: D
           Version: D1
          Platform: Other
        OS/Version: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: nobody@puremagic.com
        ReportedBy: dufresnep@gmail.com


--- Comment #0 from Paul Dufresne <dufresnep@gmail.com> 2010-11-04 18:33:30 PDT ---
I try to compile, with dmd 1.065 the following:

---
struct u64_t{
  uint lo;
  uint hi;
};

bool is_zero64(u64_t i)    {i.hi==0 && i.lo==0;}
---

but I get:
[paul@Arcturus ~]$ dmd -c test.d
test.d(7): Error: == has no effect in expression (i.lo == cast(uint)0)
test.d(7): Error: function test.is_zero64 expected to return a value of type
bool
[paul@Arcturus ~]$

and I don't seems to find a way to rewrite this without the compiler refusing it.

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Ellery Newcomer <ellery-newcomer@utulsa.edu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ellery-newcomer@utulsa.edu


--- Comment #1 from Ellery Newcomer <ellery-newcomer@utulsa.edu> 2010-11-04 18:47:15 PDT ---
(In reply to comment #0)
> I try to compile, with dmd 1.065 the following:
> 
> ---
> struct u64_t{
>   uint lo;
>   uint hi;
> };
> 
> bool is_zero64(u64_t i)    {i.hi==0 && i.lo==0;}
> ---
> 
> but I get:
> [paul@Arcturus ~]$ dmd -c test.d
> test.d(7): Error: == has no effect in expression (i.lo == cast(uint)0)
> test.d(7): Error: function test.is_zero64 expected to return a value of type
> bool
> [paul@Arcturus ~]$
> 
> and I don't seems to find a way to rewrite this without the compiler refusing it.

sure you didn't mean

bool is_zero64(u64_t i)    {return i.hi==0 && i.lo==0;}

?

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--- Comment #2 from Paul Dufresne <dufresnep@gmail.com> 2010-11-04 18:53:18 PDT ---
You are right...
I had come to think that the value returned by a function was the last
expression evaluated, and then concluded that the return could be removed...
but it seems it is not true.

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Don <clugdbug@yahoo.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|                            |clugdbug@yahoo.com.au
         Resolution|                            |INVALID


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