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digitalmars.D.bugs - [Issue 2841] New: char[] template value arguments broken in D2

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2841

           Summary: char[] template value arguments broken in D2
           Product: D
           Version: 2.027
          Platform: PC
        OS/Version: Windows
            Status: NEW
          Keywords: rejects-valid
          Severity: regression
          Priority: P2
         Component: DMD
        AssignedTo: bugzilla digitalmars.com
        ReportedBy: clugdbug yahoo.com.au


int foo(char[] c)() { return 0; }

void main(){
        int a = foo!("abc")();
}
---
fog.d(6): Error: template fog.foo(char[] c) does not match any function
template
 declaration
fog.d(6): Error: template fog.foo(char[] c) cannot deduce template function
from
 argument types !("abc")()
fog.d(6): Error: template instance errors instantiating template

This all works in D1.042. Fails in D2.028.
The code below is similar. Also for class and union.
--
struct C(char[] c){ }

void main(){
   C!("abc") a;
}


--
Apr 16 2009
next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2841






Um,

string literals are invariant(char)[].

The error message sure sucks, but it's not surprising that this doesn't work.


--
Apr 16 2009
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2841


clugdbug yahoo.com.au changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|regression                  |major
           Keywords|rejects-valid               |spec







 Um,
 
 string literals are invariant(char)[].


Indeed.


 The error message sure sucks, but it's not surprising that this doesn't work.


But there is no way that a mutable char [] could be passed as a template value
parameter. And it's not a type. So what is
template(char[] X) ?

int foo(char[] c)() { return 0; }

void main(){
   char [] z;
   int a = foo!(z)(); // ok
}

I can't see anything in the spec to indicate what this means. From the
.mangleof, it seems to be accepting it as an alias parameter.

OK, I'll change this to a spec error.


--
Apr 16 2009
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2841


Don <clugdbug yahoo.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|spec                        |accepts-invalid
            Summary|char[] template value       |char[] incorrectly accepted
                   |arguments broken in D2      |as a template value
                   |                            |argument in D2
           Severity|major                       |normal



Here's a test case which illustrates the problem better.

int foo(char[])() { return 0; }

bug.d(1): identifier expected for template value parameter

---
So it clearly thinks it is a template value parameter, but it's impossible in
D2 to have a char[] compile-time value! It must be immutable(char)[].

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Sep 22 2009
prev sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=2841


Don <clugdbug yahoo.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED



The example in comment 2 is fixed in this commit.
https://github.com/donc/dmd/commit/fc67046cf1e66182d959309fb15ef9e2d4c266b9

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Apr 15 2011