[Issue 11120] New: Compiler calls wrong property when using type tuple of length 1

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=11120

           Summary: Compiler calls wrong property when using type tuple of
                    length 1
           Product: D
           Version: D2
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P2
         Component: DMD
        AssignedTo: nobody at puremagic.com
        ReportedBy: andrej.mitrovich at gmail.com


--- Comment #0 from Andrej Mitrovic <andrej.mitrovich at gmail.com> 2013-09-24 16:04:30 PDT ---
-----
module test;

int glob;

struct K
{
    @property void max(int) { }
    @disable @property ref int max() { return glob; }

    alias setMax = _chainerFunc!max;

    template _chainerFunc(alias symbol)
    {
        import std.traits;
        alias Params = ParameterTypeTuple!symbol;

        auto ref _chainerFunc(Params[0] args)  // ok
        {
            symbol = args;
            return this;
        }
    }
}

struct F
{
    @property void max(int) { }
    @disable @property ref int max() { return glob; }

    alias setMax = _chainerFunc!max;

    template _chainerFunc(alias symbol)
    {
        import std.traits;
        alias Params = ParameterTypeTuple!symbol;

        auto ref _chainerFunc(Params args)  // fail
        {
            symbol = args;  // Error: attempts to call getter
            return this;
        }
    }
}

void main()
{
    K k;
    k.max = 2;
    k.setMax(1).setMax(2);  // chaining example

    F f;
    f.max = 2;
    f.setMax(1).setMax(2);  // ditto
}
-----

$ dmd test.d
fail.d(39): Error: function test.F.max is not callable because it is annotated
with @disable
fail.d(39): Error: cannot implicitly convert expression (tuple(_param_0)) of
type (int) to int

The code in "main()" is not needed but demonstrates the usage. Note how the
compiler wants to call the wrong @property function (the getter instead of the
setter).

The above hurts generic code having to use Params[0] when the length is already
known to equal 1.

-- Please note: The bug goes away if there is no getter property, but only a
@property setter is available. Observe:

-----
module test;

struct K
{
    @property void max(int) { }

    // commented out
    // @property int max() { return 1; }

    alias setMax = _chainerFunc!max;

    template _chainerFunc(alias symbol)
    {
        import std.traits;
        alias Params = ParameterTypeTuple!symbol;

        // ok, now works without Params[0]
        auto ref _chainerFunc(Params args)
        {
            symbol = args;
            return this;
        }
    }
}

void main()
{
    K k;
    k.max = 2;
    k.setMax(1).setMax(2);  // chaining example
}
-----

So I think this is a bug, and not an enhancement.

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