allocated_memory_swap.md

$ zig version
0.14.0-dev.1392+37df6ba86

const std = @import("std");
const fmt = std.fmt;
const debugPrint = std.debug.print;

var gpa = std.heap.GeneralPurposeAllocator(.{}){};
const allocator = gpa.allocator();

pub fn main() !void {
    var hoge = try allocator.alloc(u8, 0x10);
    _ = try fmt.bufPrint(hoge, "aaa", .{});

    debugPrint("/{s}/\n", .{hoge});
    debugPrint("hoge {p} -> {p}\n", .{ &hoge, &hoge[0] });

    const ahi = try allocator.alloc(u8, 0x10);
    _ = try fmt.bufPrint(ahi, "bbb", .{});

    debugPrint("/{s}/\n", .{ahi});
    debugPrint("ahi  {p} -> {p}\n", .{ &ahi, &ahi[0] });

    allocator.free(hoge);
    hoge = ahi;

    debugPrint("/{s}/\n", .{hoge});
    debugPrint("hoge {p} -> {p}\n", .{ &hoge, &hoge[0] });
    debugPrint("ahi  {p} -> {p}\n", .{ &ahi, &ahi[0] });

    allocator.free(ahi);
}

$ ./memswap
/aaa/
hoge []u8@7fff1ca61370 -> u8@7dcc9e927000
/bbb/
ahi  []u8@7fff1ca613e8 -> u8@7dcc9e927010
/bbb/
hoge []u8@7fff1ca61370 -> u8@7dcc9e927010
ahi  []u8@7fff1ca613e8 -> u8@7dcc9e927010