diff --git a/src/macros.rs b/src/macros.rs
index d054e8f..10d0249 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -6,18 +6,18 @@
 #[macro_export]
 macro_rules! EXTERN {
     (extern $c:tt {$(
-        fn $n:ident ($( $p:tt $(: $t:ty)*),* $(,)*) $(-> $r:ty)*;
+        fn $n:ident ($( $p:tt $(: $t:ty)?),* $(,)?) $(-> $r:ty)?;
     )+}) => {
         #[cfg_attr(all(target_env = "msvc", feature = "user"), link(name = "ntdll"))]
         #[cfg_attr(all(target_env = "msvc", feature = "kernel"), link(name = "ntoskrnl"))]
         extern $c {$(
             pub fn $n(
-                $($p $(: $t)*),*
-            ) $(-> $r)*;
+                $($p $(: $t)?),*
+            ) $(-> $r)?;
         )+}
         $(
             #[cfg(feature = "func-types")]
-            pub type $n = unsafe extern $c fn($($p $(: $t)*),*) $(-> $r)*;
+            pub type $n = unsafe extern $c fn($($p $(: $t)?),*) $(-> $r)?;
         )+
     };
     (extern $c:tt {$(
@@ -31,7 +31,7 @@ macro_rules! EXTERN {
 }
 #[macro_export]
 macro_rules! FIELD_OFFSET {
-    ($_type:ident, $field:ident$(.$cfields:ident)*) => {
+    ($_type:ty, $field:ident$(.$cfields:ident)*) => {
         unsafe {
             &(*$crate::_core::ptr::null::<$_type>()).$field$(.$cfields)* as *const _ as usize
         }
@@ -43,15 +43,15 @@ macro_rules! BITFIELD {
     ]) => {
         impl $base {$(
             #[inline]
-            pub fn $thing(&self) -> $fieldtype {
-                let size = $crate::_core::mem::size_of::<$fieldtype>() * 8;
-                self.$field << (size - $r.end) >> (size - $r.end + $r.start)
+            pub const fn $thing(&self) -> $fieldtype {
+                const SIZE: usize = $crate::_core::mem::size_of::<$fieldtype>() * 8;
+                self.$field << (SIZE - $r.end) >> (SIZE - $r.end + $r.start)
             }
             #[inline]
             pub fn $set_thing(&mut self, val: $fieldtype) {
-                let mask = ((1 << ($r.end - $r.start)) - 1) << $r.start;
-                self.$field &= !mask;
-                self.$field |= (val << $r.start) & mask;
+                const MASK: $fieldtype = ((1 << ($r.end - $r.start)) - 1) << $r.start;
+                self.$field &= !MASK;
+                self.$field |= (val << $r.start) & MASK;
             }
         )+}
     };
@@ -61,23 +61,18 @@ macro_rules! BITFIELD {
         impl $base {$(
             #[inline]
             pub unsafe fn $thing(&self) -> $fieldtype {
-                let size = $crate::_core::mem::size_of::<$fieldtype>() * 8;
-                self.$field << (size - $r.end) >> (size - $r.end + $r.start)
+                const SIZE: usize = $crate::_core::mem::size_of::<$fieldtype>() * 8;
+                self.$field << (SIZE - $r.end) >> (SIZE - $r.end + $r.start)
             }
             #[inline]
             pub unsafe fn $set_thing(&mut self, val: $fieldtype) {
-                let mask = ((1 << ($r.end - $r.start)) - 1) << $r.start;
-                self.$field &= !mask;
-                self.$field |= (val << $r.start) & mask;
+                const MASK: $fieldtype = ((1 << ($r.end - $r.start)) - 1) << $r.start;
+                self.$field &= !MASK;
+                self.$field |= (val << $r.start) & MASK;
             }
         )+}
     };
 }
-macro_rules! CTL_CODE {
-    ($DeviceType:expr, $Function:expr, $Method:expr, $Access:expr) => {
-        ($DeviceType << 16) | ($Access << 14) | ($Function << 2) | $Method
-    };
-}
 macro_rules! UNION {
     ($(#[$attrs:meta])* union $name:ident {
         $($variant:ident: $ftype:ty,)+
diff --git a/src/ntapi_base.rs b/src/ntapi_base.rs
index 575101a..bf8b8b2 100644
--- a/src/ntapi_base.rs
+++ b/src/ntapi_base.rs
@@ -11,15 +11,15 @@ pub type PRTL_ATOM = *mut RTL_ATOM;
 pub const NT_FACILITY_MASK: ULONG = 0xfff;
 pub const NT_FACILITY_SHIFT: ULONG = 16;
 #[inline]
-pub fn NT_FACILITY(Status: NTSTATUS) -> ULONG {
+pub const fn NT_FACILITY(Status: NTSTATUS) -> ULONG {
     (Status as u32) >> NT_FACILITY_SHIFT & NT_FACILITY_MASK
 }
 #[inline]
-pub fn NT_NTWIN32(Status: NTSTATUS) -> bool {
+pub const fn NT_NTWIN32(Status: NTSTATUS) -> bool {
     NT_FACILITY(Status) == FACILITY_NTWIN32 as u32
 }
 #[inline]
-pub fn WIN32_FROM_NTSTATUS(Status: NTSTATUS) -> ULONG {
+pub const fn WIN32_FROM_NTSTATUS(Status: NTSTATUS) -> ULONG {
     (Status as u32) & 0xffff
 }
 STRUCT!{struct CLIENT_ID {
diff --git a/src/ntgdi.rs b/src/ntgdi.rs
index 3d01a10..fe6c494 100644
--- a/src/ntgdi.rs
+++ b/src/ntgdi.rs
@@ -21,23 +21,23 @@ pub const GDI_HANDLE_UNIQUE_SHIFT: ULONG = 24;
 pub const GDI_HANDLE_UNIQUE_BITS: ULONG = 8;
 pub const GDI_HANDLE_UNIQUE_MASK: ULONG = 0xff;
 #[inline]
-pub fn GDI_HANDLE_INDEX(Handle: ULONG) -> ULONG {
+pub const fn GDI_HANDLE_INDEX(Handle: ULONG) -> ULONG {
     Handle & GDI_HANDLE_INDEX_MASK
 }
 #[inline]
-pub fn GDI_HANDLE_TYPE(Handle: ULONG) -> ULONG {
+pub const fn GDI_HANDLE_TYPE(Handle: ULONG) -> ULONG {
     Handle >> GDI_HANDLE_TYPE_SHIFT & GDI_HANDLE_TYPE_MASK
 }
 #[inline]
-pub fn GDI_HANDLE_ALTTYPE(Handle: ULONG) -> ULONG {
+pub const fn GDI_HANDLE_ALTTYPE(Handle: ULONG) -> ULONG {
     Handle >> GDI_HANDLE_ALTTYPE_SHIFT & GDI_HANDLE_ALTTYPE_MASK
 }
 #[inline]
-pub fn GDI_HANDLE_STOCK(Handle: ULONG) -> ULONG {
+pub const fn GDI_HANDLE_STOCK(Handle: ULONG) -> ULONG {
     Handle >> GDI_HANDLE_STOCK_SHIFT & GDI_HANDLE_STOCK_MASK
 }
 #[inline]
-pub fn GDI_MAKE_HANDLE(Index: ULONG, Unique: ULONG) -> ULONG {
+pub const fn GDI_MAKE_HANDLE(Index: ULONG, Unique: ULONG) -> ULONG {
     Unique << GDI_HANDLE_INDEX_BITS | Index
 }
 pub const GDI_DEF_TYPE: ULONG = 0;
@@ -72,12 +72,12 @@ pub const GDI_DRVOBJ_TYPE: ULONG = 28;
 pub const GDI_DCIOBJ_TYPE: ULONG = 29;
 pub const GDI_SPOOL_TYPE: ULONG = 30;
 #[inline]
-pub fn GDI_CLIENT_TYPE_FROM_HANDLE(Handle: ULONG) -> ULONG {
+pub const fn GDI_CLIENT_TYPE_FROM_HANDLE(Handle: ULONG) -> ULONG {
     Handle & (GDI_HANDLE_ALTTYPE_MASK << GDI_HANDLE_ALTTYPE_SHIFT | GDI_HANDLE_TYPE_MASK
         << GDI_HANDLE_TYPE_SHIFT)
 }
 #[inline]
-pub fn GDI_CLIENT_TYPE_FROM_UNIQUE(Unique: ULONG) -> ULONG {
+pub const fn GDI_CLIENT_TYPE_FROM_UNIQUE(Unique: ULONG) -> ULONG {
     GDI_CLIENT_TYPE_FROM_HANDLE(Unique << 16)
 }
 pub const GDI_ALTTYPE_1: ULONG = 1 << GDI_HANDLE_ALTTYPE_SHIFT;
diff --git a/src/ntioapi.rs b/src/ntioapi.rs
index 265c6f1..269732a 100644
--- a/src/ntioapi.rs
+++ b/src/ntioapi.rs
@@ -4,6 +4,7 @@
 // http://opensource.org/licenses/MIT>, at your option. This file may not be
 // copied, modified, or distributed except according to those terms.
 use crate::string::UTF16Const;
+use crate::winapi_local::um::winioctl::CTL_CODE;
 use winapi::shared::basetsd::ULONG_PTR;
 use winapi::shared::guiddef::GUID;
 use winapi::shared::minwindef::DWORD;
@@ -1346,47 +1347,47 @@ pub const DEVICE_NAMED_PIPE: UTF16Const = UTF16Const(&[
     0x0064, 0x0050, 0x0069, 0x0070, 0x0065, 0x005C, 0u16,
 ]);
 pub const FSCTL_PIPE_ASSIGN_EVENT: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 0, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_DISCONNECT: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 1, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_LISTEN: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 2, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_PEEK: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 3, METHOD_BUFFERED, FILE_READ_DATA);
-pub const FSCTL_PIPE_QUERY_EVENT: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 4, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_TRANSCEIVE: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 5, METHOD_NEITHER, FILE_READ_DATA | FILE_WRITE_DATA);
-pub const FSCTL_PIPE_WAIT: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 6, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_IMPERSONATE: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 7, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_SET_CLIENT_PROCESS: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 8, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_QUERY_CLIENT_PROCESS: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 9, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_GET_PIPE_ATTRIBUTE: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 10, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_SET_PIPE_ATTRIBUTE: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 11, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_GET_CONNECTION_ATTRIBUTE: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 12, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_SET_CONNECTION_ATTRIBUTE: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 13, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_GET_HANDLE_ATTRIBUTE: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 14, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_SET_HANDLE_ATTRIBUTE: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 15, METHOD_BUFFERED, FILE_ANY_ACCESS);
-pub const FSCTL_PIPE_FLUSH: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 16, METHOD_BUFFERED, FILE_WRITE_DATA);
-pub const FSCTL_PIPE_INTERNAL_READ: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 2045, METHOD_BUFFERED, FILE_READ_DATA);
-pub const FSCTL_PIPE_INTERNAL_WRITE: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 2046, METHOD_BUFFERED, FILE_WRITE_DATA);
-pub const FSCTL_PIPE_INTERNAL_TRANSCEIVE: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 2047, METHOD_NEITHER, FILE_READ_DATA | FILE_WRITE_DATA);
-pub const FSCTL_PIPE_INTERNAL_READ_OVFLOW: u32 =
-    CTL_CODE!(FILE_DEVICE_NAMED_PIPE, 2048, METHOD_BUFFERED, FILE_READ_DATA);
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 0, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_DISCONNECT: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 1, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_LISTEN: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 2, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_PEEK: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 3, METHOD_BUFFERED, FILE_READ_DATA);
+pub const FSTL_PIPE_QUERY_EVENT: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 4, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_TRANSCEIVE: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 5, METHOD_NEITHER, FILE_READ_DATA | FILE_WRITE_DATA);
+pub const FSTL_PIPE_WAIT: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 6, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_IMPERSONATE: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 7, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_SET_CLIENT_PROCESS: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 8, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_QUERY_CLIENT_PROCESS: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 9, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_GET_PIPE_ATTRIBUTE: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 10, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_SET_PIPE_ATTRIBUTE: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 11, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_GET_CONNECTION_ATTRIBUTE: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 12, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_SET_CONNECTION_ATTRIBUTE: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 13, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_GET_HANDLE_ATTRIBUTE: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 14, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_SET_HANDLE_ATTRIBUTE: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 15, METHOD_BUFFERED, FILE_ANY_ACCESS);
+pub const FSTL_PIPE_FLUSH: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 16, METHOD_BUFFERED, FILE_WRITE_DATA);
+pub const FSTL_PIPE_INTERNAL_READ: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 2045, METHOD_BUFFERED, FILE_READ_DATA);
+pub const FSTL_PIPE_INTERNAL_WRITE: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 2046, METHOD_BUFFERED, FILE_WRITE_DATA);
+pub const FSTL_PIPE_INTERNAL_TRANSCEIVE: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 2047, METHOD_NEITHER, FILE_READ_DATA | FILE_WRITE_DATA);
+pub const FSTL_PIPE_INTERNAL_READ_OVFLOW: u32 =
+    CTL_CODE(FILE_DEVICE_NAMED_PIPE, 2048, METHOD_BUFFERED, FILE_READ_DATA);
 pub const FILE_PIPE_READ_DATA: u32 = 0x00000000;
 pub const FILE_PIPE_WRITE_SPACE: u32 = 0x00000001;
 STRUCT!{struct FILE_PIPE_ASSIGN_EVENT_BUFFER {
@@ -1433,7 +1434,7 @@ pub type PFILE_PIPE_CLIENT_PROCESS_BUFFER_EX = *mut FILE_PIPE_CLIENT_PROCESS_BUF
 pub const MAILSLOT_CLASS_FIRSTCLASS: u32 = 1;
 pub const MAILSLOT_CLASS_SECONDCLASS: u32 = 2;
 pub const FSCTL_MAILSLOT_PEEK: u32 =
-    CTL_CODE!(FILE_DEVICE_MAILSLOT, 0, METHOD_NEITHER, FILE_READ_DATA);
+    CTL_CODE(FILE_DEVICE_MAILSLOT, 0, METHOD_NEITHER, FILE_READ_DATA);
 STRUCT!{struct FILE_MAILSLOT_PEEK_BUFFER {
     ReadDataAvailable: ULONG,
     NumberOfMessages: ULONG,
diff --git a/src/ntldr.rs b/src/ntldr.rs
index 911fdd1..af0e3d4 100644
--- a/src/ntldr.rs
+++ b/src/ntldr.rs
@@ -197,16 +197,16 @@ BITFIELD!{unsafe LDR_DATA_TABLE_ENTRY_u2 Flags: ULONG [
 ]}
 pub type PLDR_DATA_TABLE_ENTRY = *mut LDR_DATA_TABLE_ENTRY;
 #[inline]
-pub fn LDR_IS_DATAFILE(DllHandle: ULONG_PTR) -> bool {
+pub const fn LDR_IS_DATAFILE(DllHandle: ULONG_PTR) -> bool {
     DllHandle & 1 != 0
 }
 #[inline]
-pub fn LDR_IS_IMAGEMAPPING(DllHandle: ULONG_PTR) -> bool {
+pub const fn LDR_IS_IMAGEMAPPING(DllHandle: ULONG_PTR) -> bool {
     DllHandle & 2 != 0
 }
 #[inline]
-pub fn LDR_IS_RESOURCE(DllHandle: ULONG_PTR) -> bool {
-    LDR_IS_IMAGEMAPPING(DllHandle) || LDR_IS_DATAFILE(DllHandle)
+pub const fn LDR_IS_RESOURCE(DllHandle: ULONG_PTR) -> bool {
+    (LDR_IS_IMAGEMAPPING(DllHandle) | LDR_IS_DATAFILE(DllHandle)) as u8 != 0 //fixme
 }
 EXTERN!{extern "system" {
     fn LdrLoadDll(
diff --git a/src/ntpsapi.rs b/src/ntpsapi.rs
index 3193cee..05bd2b0 100644
--- a/src/ntpsapi.rs
+++ b/src/ntpsapi.rs
@@ -563,7 +563,7 @@ pub const PS_PROTECTED_SIGNER_MASK: UCHAR = 0xFF;
 pub const PS_PROTECTED_AUDIT_MASK: UCHAR = 0x08;
 pub const PS_PROTECTED_TYPE_MASK: UCHAR = 0x07;
 #[inline]
-pub fn PsProtectedValue(
+pub const fn PsProtectedValue(
     aSigner: PS_PROTECTED_SIGNER,
     aAudit: u8,
     aType: PS_PROTECTED_TYPE,
@@ -1084,14 +1084,14 @@ ENUM!{enum PS_ATTRIBUTE_NUM {
     PsAttributeMax = 27,
 }}
 #[inline]
-pub fn PsAttributeValue(
+pub const fn PsAttributeValue(
     Number: PS_ATTRIBUTE_NUM,
     Thread: bool,
     Input: bool,
     Additive: bool,
-) -> ULONG_PTR {
-    (Number & PS_ATTRIBUTE_NUMBER_MASK | if Thread { PS_ATTRIBUTE_THREAD } else { 0 }
-    | if Input { PS_ATTRIBUTE_INPUT } else { 0 } | if Additive { PS_ATTRIBUTE_ADDITIVE } else { 0 }
+) -> ULONG_PTR { //fixme
+    (Number & PS_ATTRIBUTE_NUMBER_MASK | [0, PS_ATTRIBUTE_THREAD][Thread as usize]
+    | [0, PS_ATTRIBUTE_INPUT][Input as usize] | [0, PS_ATTRIBUTE_ADDITIVE][Additive as usize]
     ) as usize
 }
 pub const PS_ATTRIBUTE_PARENT_PROCESS: ULONG_PTR = 0x00060000;
diff --git a/src/ntrtl.rs b/src/ntrtl.rs
index 7a3d699..ea05860 100644
--- a/src/ntrtl.rs
+++ b/src/ntrtl.rs
@@ -249,15 +249,15 @@ pub fn RtlInitializeSplayLinks(Links: &mut RTL_SPLAY_LINKS) {
     Links.RightChild = null_mut();
 }
 #[inline]
-pub fn RtlParent(Links: &RTL_SPLAY_LINKS) -> PRTL_SPLAY_LINKS {
+pub const fn RtlParent(Links: &RTL_SPLAY_LINKS) -> PRTL_SPLAY_LINKS {
     Links.Parent
 }
 #[inline]
-pub fn RtlLeftChild(Links: &RTL_SPLAY_LINKS) -> PRTL_SPLAY_LINKS {
+pub const fn RtlLeftChild(Links: &RTL_SPLAY_LINKS) -> PRTL_SPLAY_LINKS {
     Links.LeftChild
 }
 #[inline]
-pub fn RtlRightChild(Links: &RTL_SPLAY_LINKS) -> PRTL_SPLAY_LINKS {
+pub const fn RtlRightChild(Links: &RTL_SPLAY_LINKS) -> PRTL_SPLAY_LINKS {
     Links.RightChild
 }
 #[inline]
@@ -417,7 +417,7 @@ STRUCT!{struct RTL_DYNAMIC_HASH_TABLE_ENTRY {
 }}
 pub type PRTL_DYNAMIC_HASH_TABLE_ENTRY = *mut RTL_DYNAMIC_HASH_TABLE_ENTRY;
 #[inline]
-pub fn HASH_ENTRY_KEY(x: &RTL_DYNAMIC_HASH_TABLE_ENTRY) -> ULONG_PTR {
+pub const fn HASH_ENTRY_KEY(x: &RTL_DYNAMIC_HASH_TABLE_ENTRY) -> ULONG_PTR {
     x.Signature
 }
 STRUCT!{struct RTL_DYNAMIC_HASH_TABLE_CONTEXT {
@@ -459,23 +459,23 @@ pub fn RtlInitHashTableContextFromEnumerator(
 }
 // RtlReleaseHashTableContext
 #[inline]
-pub fn RtlTotalBucketsHashTable(HashTable: &RTL_DYNAMIC_HASH_TABLE) -> ULONG {
+pub const fn RtlTotalBucketsHashTable(HashTable: &RTL_DYNAMIC_HASH_TABLE) -> ULONG {
     HashTable.TableSize
 }
 #[inline]
-pub fn RtlNonEmptyBucketsHashTable(HashTable: &RTL_DYNAMIC_HASH_TABLE) -> ULONG {
+pub const fn RtlNonEmptyBucketsHashTable(HashTable: &RTL_DYNAMIC_HASH_TABLE) -> ULONG {
     HashTable.NonEmptyBuckets
 }
 #[inline]
-pub fn RtlEmptyBucketsHashTable(HashTable: &RTL_DYNAMIC_HASH_TABLE) -> ULONG {
+pub const fn RtlEmptyBucketsHashTable(HashTable: &RTL_DYNAMIC_HASH_TABLE) -> ULONG {
     HashTable.TableSize - HashTable.NonEmptyBuckets
 }
 #[inline]
-pub fn RtlTotalEntriesHashTable(HashTable: &RTL_DYNAMIC_HASH_TABLE) -> ULONG {
+pub const fn RtlTotalEntriesHashTable(HashTable: &RTL_DYNAMIC_HASH_TABLE) -> ULONG {
     HashTable.NumEntries
 }
 #[inline]
-pub fn RtlActiveEnumeratorsHashTable(HashTable: &RTL_DYNAMIC_HASH_TABLE) -> ULONG {
+pub const fn RtlActiveEnumeratorsHashTable(HashTable: &RTL_DYNAMIC_HASH_TABLE) -> ULONG {
     HashTable.NumEnumerators
 }
 EXTERN!{extern "system" {
@@ -2490,22 +2490,19 @@ EXTERN!{extern "system" {
     ) -> LOGICAL;
 }}
 #[inline]
-pub fn RtlIsEqualLuid(L1: &LUID, L2: &LUID) -> bool {
-    L1.LowPart == L2.LowPart && L1.HighPart == L2.HighPart
+pub const fn RtlIsEqualLuid(L1: &LUID, L2: &LUID) -> bool {
+    ((L1.LowPart == L2.LowPart) & (L1.HighPart == L2.HighPart)) as u8 != 0 //fixme
 }
 #[inline]
-pub fn RtlIsZeroLuid(L1: &LUID) -> bool {
+pub const fn RtlIsZeroLuid(L1: &LUID) -> bool {
     (L1.LowPart | L1.HighPart as u32) == 0
 }
 #[inline]
-pub unsafe fn RtlConvertLongToLuid(Long: LONG) -> LUID {
-    use core::mem::uninitialized;
-    let mut tempLi: LARGE_INTEGER = uninitialized();
-    *tempLi.QuadPart_mut() = Long as i64;
-    LUID { LowPart: tempLi.s().LowPart, HighPart: tempLi.s().HighPart }
+pub const fn RtlConvertLongToLuid(Long: LONG) -> LUID {
+    LUID { LowPart: Long as u32, HighPart: ((Long as i64) >> 32) as i32 }
 }
 #[inline]
-pub fn RtlConvertUlongToLuid(Ulong: ULONG) -> LUID {
+pub const fn RtlConvertUlongToLuid(Ulong: ULONG) -> LUID {
     LUID { LowPart: Ulong, HighPart: 0 }
 }
 EXTERN!{extern "system" {
diff --git a/src/winapi_local/um.rs b/src/winapi_local/um.rs
index 9bdf106..2708e58 100644
--- a/src/winapi_local/um.rs
+++ b/src/winapi_local/um.rs
@@ -3,4 +3,5 @@
 // http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
 // http://opensource.org/licenses/MIT>, at your option. This file may not be
 // copied, modified, or distributed except according to those terms.
+pub(crate) mod winioctl;
 pub mod winnt;
diff --git a/src/winapi_local/um/winioctl.rs b/src/winapi_local/um/winioctl.rs
new file mode 100644
index 0000000..da49026
--- /dev/null
+++ b/src/winapi_local/um/winioctl.rs
@@ -0,0 +1,4 @@
+#[inline]
+pub(crate) const fn CTL_CODE(DeviceType: u32, Function: u32, Method: u32, Access: u32) -> u32 {
+    (DeviceType << 16) | (Access << 14) | (Function << 2) | Method
+}
diff --git a/src/winapi_local/um/winnt.rs b/src/winapi_local/um/winnt.rs
index f95cc38..05e234d 100644
--- a/src/winapi_local/um/winnt.rs
+++ b/src/winapi_local/um/winnt.rs
@@ -4,7 +4,7 @@
 // http://opensource.org/licenses/MIT>, at your option. This file may not be
 // copied, modified, or distributed except according to those terms.
 #[inline]
-pub fn UInt32x32To64(a: u32, b: u32) -> u64 {
+pub const fn UInt32x32To64(a: u32, b: u32) -> u64 {
     a as u64 * b as u64
 }
 #[cfg(feature = "nightly")]