From be86e41d975325d30145e30369912a409012b76b Mon Sep 17 00:00:00 2001
From: daurnimator <quae@daurnimator.com>
Date: Wed, 13 Nov 2019 15:37:21 +1100
Subject: [PATCH] std: add CTL_CODE function for windows

---
 lib/std/os/windows/bits.zig | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/std/os/windows/bits.zig b/lib/std/os/windows/bits.zig
index 3dc772a7c3..2f65c27e47 100644
--- a/lib/std/os/windows/bits.zig
+++ b/lib/std/os/windows/bits.zig
@@ -166,6 +166,14 @@ pub const FILE_ANY_ACCESS = 0;
 pub const FILE_READ_ACCESS = 1;
 pub const FILE_WRITE_ACCESS = 2;
 
+/// https://docs.microsoft.com/en-us/windows-hardware/drivers/kernel/defining-i-o-control-codes
+pub fn CTL_CODE(deviceType: u16, function: u12, method: TransferType, access: u2) DWORD {
+    return (@as(DWORD, deviceType) << 16) |
+        (@as(DWORD, access) << 14) |
+        (@as(DWORD, function) << 2) |
+        @enumToInt(method);
+}
+
 pub const INVALID_HANDLE_VALUE = @intToPtr(HANDLE, maxInt(usize));
 
 pub const INVALID_FILE_ATTRIBUTES = @as(DWORD, maxInt(DWORD));