zig

commit eac2bbfec9f99c27a886f4842cb9ca42584607f3 (tree)
parent 1872c85ac25146036119387d1f376e2cba3ff7be
Author: Andrew Kelley <andrew@ziglang.org>
Date:   Mon,  8 Sep 2025 18:18:27 -0700

std.Io.Writer.writeSliceEndian: add compile error

check when an auto-layout struct is attempted to be memory reinterpreted
and written out. it would be writing undefined memory

Diffstat:
M
lib/std/Io/Writer.zig
 | 
5
+++++

1 file changed, 5 insertions(+), 0 deletions(-)
diff --git a/lib/std/Io/Writer.zig b/lib/std/Io/Writer.zig
@@ -865,6 +865,11 @@ pub inline fn writeSliceEndian(
     slice: []const Elem,
     endian: std.builtin.Endian,
 ) Error!void {
+    switch (@typeInfo(Elem)) {
+        .@"struct" => |info| comptime assert(info.layout != .auto),
+        .int, .@"enum" => {},
+        else => @compileError("ill-defined memory layout"),
+    }
     if (native_endian == endian) {
         return writeAll(w, @ptrCast(slice));
     } else {