Generic index

[Thierry Delisle]

forall( dtype T )
struct ptr_t {
	T * ptr;
};

forall( dtype T | sized( T ) )
T& ?[?]( ptr_t( T ) & this, ptrdiff_t idx ) {
	return this.ptr[idx];
}

yields

test.c: In function ‘___operator_index__A0_1_0_0__FRd0_R6sptr_tl__1’:
test.c:22:56: warning: dereferencing ‘void *’ pointer
 }
                                                        ^
test.c:22:5: error: invalid use of void expression
 }

[Rob Schluntz]

I took a quick look at this. Prior to the Box pass, this code looks right:

struct ptr_t {
    void *__ptr__P2tT_1;
};

T *___operator_index__A0_1_0_0__FRd0_R6sptr_tl__1(ptr_t(T )  *__this__R6sptr_t_1, signed long int __idx__l_1){
    return ((T *)(&(*__this__R6sptr_t_1).__ptr__P2tT_1[__idx__l_1]));
}

But the Box pass does not correctly handle this use of subscripting, since ptr_t is dtype-static and has already been monomorphized. If you add the sized(T) assertion to the ptr_t definition, it works since ptr_t is not monomorphized.

[Thierry Delisle]

This works as a workaround :

forall( dtype T )
struct ptr_t {
	T * ptr;
};

forall( dtype T | sized( T ) )
T& ?[?]( ptr_t( T ) & this, ptrdiff_t idx ) {
	return ((typeof(this.ptr))this.ptr)[idx];
}

[Rob Schluntz <rschlunt@…>]

In b95fe40:

Add casts to dtype-static member expressions to prevent loss of type information [fixes #42] [fixes #59]