add behavior test for comptime pointer casting

closes #1150
closes #1292
closes #4093

1 files changed, 31 insertions, 0 deletions

diff --git a/test/behavior/ptrcast.zig b/test/behavior/ptrcast.zig
index 982a0b862f..f25161ece8 100644
--- a/test/behavior/ptrcast.zig
+++ b/test/behavior/ptrcast.zig
@@ -203,6 +203,37 @@ test "comptime ptrcast keeps larger alignment" {
     }
 }
 
+test "ptrcast of const integer has the correct object size" {
+    const is_value = ~@intCast(isize, std.math.minInt(isize));
+    const is_bytes = @ptrCast([*]const u8, &is_value)[0..@sizeOf(isize)];
+    if (@sizeOf(isize) == 8) {
+        switch (native_endian) {
+            .Little => {
+                try expect(is_bytes[0] == 0xff);
+                try expect(is_bytes[1] == 0xff);
+                try expect(is_bytes[2] == 0xff);
+                try expect(is_bytes[3] == 0xff);
+
+                try expect(is_bytes[4] == 0xff);
+                try expect(is_bytes[5] == 0xff);
+                try expect(is_bytes[6] == 0xff);
+                try expect(is_bytes[7] == 0x7f);
+            },
+            .Big => {
+                try expect(is_bytes[0] == 0x7f);
+                try expect(is_bytes[1] == 0xff);
+                try expect(is_bytes[2] == 0xff);
+                try expect(is_bytes[3] == 0xff);
+
+                try expect(is_bytes[4] == 0xff);
+                try expect(is_bytes[5] == 0xff);
+                try expect(is_bytes[6] == 0xff);
+                try expect(is_bytes[7] == 0xff);
+            },
+        }
+    }
+}
+
 test "implicit optional pointer to optional anyopaque pointer" {
     if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO