// Zig provides a level of safety, where problems may be found during execution.
// Safety can be left on, or turned off.
// Zig has many cases of so-called `detectable illegal behaviour`,
// meaning that illegal behaviour will be caught (causing a panic) with safety on,
// but will result in undefined behaviour with safety off.
// Users are strongly recommended to develop and test their software with safety on, despite its speed penalties.

// For example, runtime safety protects you from out of bounds indices.

test "out of bounds" {
    const a = [3]u8{ 1, 2, 3 };
    var index: u8 = 5;
    const b = a[index];

    _ = b;
    index = index;
}

// test "out of bounds"...index out of bounds
// .\tests.zig:43:14: 0x7ff698cc1b82 in test "out of bounds" (test.obj)
//    const b = a[index];
//             ^

// The user may disable runtime safety for the current block using the built-in function `@setRuntimeSafety`.
test "out of bounds, no safety" {
    @setRuntimeSafety(true);
    // defer @setRuntimeSafety(false);
    const a = [3]u8{ 1, 2, 3 };
    var index: u8 = 5;
    const b = a[index]; // no panic

    _ = b;
    index = index; // no panic
}

// Safety is off for some build modes (to be discussed later).