id	summary	reporter	owner	description	type	status	priority	component	version	resolution	keywords	cc
214	Assertion with sized generic parameter breaks the declaring function's body	m3zulfiq		"A sized generic struct cannot be instantiated in a function with an assertion that takes this struct as a parameter.

{{{
forall( otype X )
struct wrapper { X item; };

forall( otype Y 
                #ifndef HIDE_ERROR
                                    | { void unusedHelper( wrapper(Y) ); }
                #endif
      )
void f() {
    wrapper(Y) myvar;
}
}}}

Actual (plain): GCC error: '_sizeof_S7wrapper_Y1Y_' undeclared 
Actual (-DHIDE_ERROR), Expected (both):  Compiler success

Desired for the following case in the memory allocator.  Here, the affected function is `balloc`, whose assertion for `$balloc_internal` takes a parameter of type `SS_fill(T)`.  In the affected function's body, the object declaration where the failure happens is the `(SS_fill(T)){...}` argument initializer.
{{{
forall( dtype T | sized(T) ) {
	union  U_fill 	{ char c; T * a; T t; };
	struct SS_fill 	{ char tag; U_fill(T) fill; };
}

static inline forall( dtype T | sized(T) ) {
	T * $balloc_internal( void * Resize, void * Realloc, size_t Align, size_t Dim, SS_fill(T) Fill) {
		return (T*)0p;
	} // $balloc_internal

	forall( ttype TT | { T * $balloc_internal( void *, void *, size_t, size_t, SS_fill(T), TT ); } ) {
	    T * balloc( TT all ) {
	        return $balloc_internal( (void*)0p, (void*)0p, 16, 1, (SS_fill(T)){'0', (U_fill(T)){'0'}}, all);
	    } // balloc
	} // distribution TT
} // distribution T

int main() {
	int * abc = balloc();
	free(abc);
	return 0;
}
}}}
Actual:  GCC error: '_sizeof_S7SS_fill_Y1T_' undeclared 
Expected:  Compiler success

This revision shows the assertion is at fault (but it does not provide a workaround).  The assumption of a TT-fitting `$balloc_internal` is changed from an assertion to a declaration.
{{{
forall( dtype T | sized(T) ) {
	union  U_fill 	{ char c; T * a; T t; };
	struct SS_fill 	{ char tag; U_fill(T) fill; };
}

static inline forall( dtype T | sized(T) ) {
	T * $balloc_internal( void * Resize, void * Realloc, size_t Align, size_t Dim, SS_fill(T) Fill) {
		return (T*)0p;
	} // $balloc_internal

	forall( ttype TT ) {
	    T * $balloc_internal( void *, void *, size_t, size_t, SS_fill(T), TT );
	    T * balloc( TT all ) {
	        return $balloc_internal( (void*)0p, (void*)0p, 16, 1, (SS_fill(T)){'0', (U_fill(T)){'0'}}, all);
	    } // balloc
	} // distribution TT
} // distribution T

int main() {
	int * abc = balloc();
	free(abc);
	return 0;
}
}}}
Actual and expected: Compiler success, linker failure to find `$balloc_internal( ..., TT )`.
"	defect	closed	major	cfa-cc	1.0	fixed	dtype, ttype, generic struct, union