zig/test/behavior/bugs/1076.zig

const std = @import("std");
const builtin = @import("builtin");
const mem = std.mem;
const expect = std.testing.expect;

test "comptime code should not modify constant data" {
    if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest;
    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;

    try testCastPtrOfArrayToSliceAndPtr();
    comptime try testCastPtrOfArrayToSliceAndPtr();
}

fn testCastPtrOfArrayToSliceAndPtr() !void {
    {
        var array = "aoeu".*;
        const x: [*]u8 = &array;
        x[0] += 1;
        try expect(mem.eql(u8, array[0..], "boeu"));
    }
    {
        var array: [4]u8 = "aoeu".*;
        const x: [*]u8 = &array;
        x[0] += 1;
        try expect(mem.eql(u8, array[0..], "boeu"));
    }
}