// C.4 — @[Release] zero-cost path vs @[Checked]
// Default / Release: free; Checked: catches double-mut and dangling returns.
import Std::Io::{PrintLine, PrintInt};
import Std::Test::{Test_AssertEqInt, Test_Pass};

// Tier 1 — unchecked (default)
func UncheckedInc(p: *int) {
    *p = *p + 1;
}

// Tier 2 — borrow checked API surface
@[Checked]
func SafeInc(p: &mut int) {
    *p = *p + 1;
}

@[Checked]
func SafeGet(p: &int) -> int {
    return *p;
}

// Tier 3 — explicit zero-cost hot path (Release wins over Checked)
@[Checked]
@[Release]
func HotInc(p: &mut int) {
    // Would be fine either way; attribute documents "no checker cost here"
    *p = *p + 1;
}

@[Release]
func HotDangle() -> &int {
    // Allowed: Release disables dangling-return checks
    var x: int = 99;
    return &x;
}

func Main() -> int {
    var n: int = 10;
    UncheckedInc(&n);
    Test_AssertEqInt(n, 11);

    SafeInc(&n);
    Test_AssertEqInt(n, 12);

    HotInc(&n);
    Test_AssertEqInt(n, 13);

    let v: int = SafeGet(&n);
    Test_AssertEqInt(v, 13);

    // HotDangle is only used to prove Release compiles; do not dereference
    discard HotDangle();

    PrintInt(n);
    PrintLine("");
    Test_Pass("ownership_release");
    return 0;
}