id	summary	reporter	owner	description	type	status	priority	component	version	resolution	keywords	cc
189	Reference and pointer types allow unsound initialization	mlbrooks		"This code implies a reinterpret pointer cast.  But the code does not do a cast.
{{{
int main() {
    float x = 3.14;
    float & xx = x;
    int & yy = xx;  // not sound
    int y = yy;
    printf(""%d\n"", y);
}
}}}

Expected: Compiler error at ""not sound"" line, saying cannot initialize int & from float &.

Actual: Compiler success; program prints 1078523331 which is the decimal value of 0x4048f5c3, which is the IEEE 754 representation of 3.14.

Note that this unsoundness also happens at function return.

This allows for:
{{{
forall (dtype T, dtype S)
T & anycvt( S & s ) {
    return s; // not sound
}
int main() {
    float x = 3.14;
    int y = anycvt(x);
    printf(""%d\n"", y);
}
}}}

Expected: Compiler error at ""not sound"" line, saying cannot initialize T & from S &.

Actual: Compiler success; program prints 1078523331.

This behaviour also occurs with pointers.  Furthermore, this example is trimmed such that it can run with -n (no prelude).

{{{
struct A {};
struct B {};

void f() {
    A * ap;
    B * bp = ap; // not sound
}
}}}

Expected: Compiler error at ""not sound"" line, saying cannot initialize B* from A*.

Actual: `cfa-cpp -n -P astexpr -P ascodegen` produces output in which the ""unsound"" line is `B *_X2bpPS1B_2 = ((B *)_X2apPS1A_2);`.
"	defect	closed	major	cfa-cc	1.0	fixed