[Issue 2448] template return by reference causes seg fault

[d-bugmail at puremagic.com]

http://d.puremagic.com/issues/show_bug.cgi?id=2448


andrei at metalanguage.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |major




------- Comment #1 from andrei at metalanguage.com  2009-01-25 23:32 -------
Adding another example and bumping this to major because it stops std.algorithm
development dead in its tracks.

template ElementType(R)
{
    alias typeof({ R r; return r[0]; }()) ElementType;
}

bool empty(T)(in T[] a) { return !a.length; }
void next(T)(ref T[] a) { assert(a.length); a = a[1 .. $]; }
void retreat(T)(ref T[] a) { assert(a.length); a = a[0 .. $ - 1]; }
T head(T)(T[] a) { assert(a.length); return a[0]; }
ref T toe(T)(T[] a) { assert(a.length); return a[a.length - 1]; }

struct Retro(R)
{
private:
    R _input;

public:
    bool empty()
    {
        return _input.empty;
    }

    void next()
    {
        _input.retreat;
    }

    ElementType!(R) head()
    {
        return _input.toe;
    }
}

void main()
{
    void test(int[] input)
    {
        foreach (e; Retro!(int[])(input))
        {
        }
    }
    test([ 1 ]);
}


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