{- |
Copyright  : Will Thompson, Iñaki García Etxebarria and Jonas Platte
License    : LGPL-2.1
Maintainer : Iñaki García Etxebarria (garetxe@gmail.com)

An opaque structure representing a checksumming operation.
To create a new GChecksum, use 'GI.GLib.Structs.Checksum.checksumNew'. To free
a GChecksum, use 'GI.GLib.Structs.Checksum.checksumFree'.

/Since: 2.16/
-}

#define ENABLE_OVERLOADING \
       (!defined(__HADDOCK_VERSION__))

module GI.GLib.Structs.Checksum
    ( 

-- * Exported types
    Checksum(..)                            ,
    noChecksum                              ,


 -- * Methods
-- ** copy #method:copy#

#if ENABLE_OVERLOADING
    ChecksumCopyMethodInfo                  ,
#endif
    checksumCopy                            ,


-- ** free #method:free#

#if ENABLE_OVERLOADING
    ChecksumFreeMethodInfo                  ,
#endif
    checksumFree                            ,


-- ** getString #method:getString#

#if ENABLE_OVERLOADING
    ChecksumGetStringMethodInfo             ,
#endif
    checksumGetString                       ,


-- ** new #method:new#

    checksumNew                             ,


-- ** reset #method:reset#

#if ENABLE_OVERLOADING
    ChecksumResetMethodInfo                 ,
#endif
    checksumReset                           ,


-- ** typeGetLength #method:typeGetLength#

    checksumTypeGetLength                   ,


-- ** update #method:update#

#if ENABLE_OVERLOADING
    ChecksumUpdateMethodInfo                ,
#endif
    checksumUpdate                          ,




    ) where

import Data.GI.Base.ShortPrelude
import qualified Data.GI.Base.ShortPrelude as SP
import qualified Data.GI.Base.Overloading as O
import qualified Prelude as P

import qualified Data.GI.Base.Attributes as GI.Attributes
import qualified Data.GI.Base.ManagedPtr as B.ManagedPtr
import qualified Data.GI.Base.GError as B.GError
import qualified Data.GI.Base.GVariant as B.GVariant
import qualified Data.GI.Base.GValue as B.GValue
import qualified Data.GI.Base.GParamSpec as B.GParamSpec
import qualified Data.GI.Base.CallStack as B.CallStack
import qualified Data.Text as T
import qualified Data.ByteString.Char8 as B
import qualified Data.Map as Map
import qualified Foreign.Ptr as FP

import {-# SOURCE #-} qualified GI.GLib.Enums as GLib.Enums

-- | Memory-managed wrapper type.
newtype Checksum = Checksum (ManagedPtr Checksum)
foreign import ccall "g_checksum_get_type" c_g_checksum_get_type :: 
    IO GType

instance BoxedObject Checksum where
    boxedType :: Checksum -> IO GType
boxedType _ = IO GType
c_g_checksum_get_type

-- | A convenience alias for `Nothing` :: `Maybe` `Checksum`.
noChecksum :: Maybe Checksum
noChecksum :: Maybe Checksum
noChecksum = Maybe Checksum
forall a. Maybe a
Nothing


#if ENABLE_OVERLOADING
instance O.HasAttributeList Checksum
type instance O.AttributeList Checksum = ChecksumAttributeList
type ChecksumAttributeList = ('[ ] :: [(Symbol, *)])
#endif

-- method Checksum::new
-- method type : Constructor
-- Args : [Arg {argCName = "checksum_type", argType = TInterface (Name {namespace = "GLib", name = "ChecksumType"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "the desired type of checksum", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- Lengths : []
-- returnType : Just (TInterface (Name {namespace = "GLib", name = "Checksum"}))
-- throws : False
-- Skip return : False

foreign import ccall "g_checksum_new" g_checksum_new :: 
    CUInt ->                                -- checksum_type : TInterface (Name {namespace = "GLib", name = "ChecksumType"})
    IO (Ptr Checksum)

{- |
Creates a new 'GI.GLib.Structs.Checksum.Checksum', using the checksum algorithm /@checksumType@/.
If the /@checksumType@/ is not known, 'Nothing' is returned.
A 'GI.GLib.Structs.Checksum.Checksum' can be used to compute the checksum, or digest, of an
arbitrary binary blob, using different hashing algorithms.

A 'GI.GLib.Structs.Checksum.Checksum' works by feeding a binary blob through 'GI.GLib.Structs.Checksum.checksumUpdate'
until there is data to be checked; the digest can then be extracted
using 'GI.GLib.Structs.Checksum.checksumGetString', which will return the checksum as a
hexadecimal string; or @/g_checksum_get_digest()/@, which will return a
vector of raw bytes. Once either 'GI.GLib.Structs.Checksum.checksumGetString' or
@/g_checksum_get_digest()/@ have been called on a 'GI.GLib.Structs.Checksum.Checksum', the checksum
will be closed and it won\'t be possible to call 'GI.GLib.Structs.Checksum.checksumUpdate'
on it anymore.

/Since: 2.16/
-}
checksumNew ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    GLib.Enums.ChecksumType
    {- ^ /@checksumType@/: the desired type of checksum -}
    -> m Checksum
    {- ^ __Returns:__ the newly created 'GI.GLib.Structs.Checksum.Checksum', or 'Nothing'.
  Use 'GI.GLib.Structs.Checksum.checksumFree' to free the memory allocated by it. -}
checksumNew :: ChecksumType -> m Checksum
checksumNew checksumType :: ChecksumType
checksumType = IO Checksum -> m Checksum
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO Checksum -> m Checksum) -> IO Checksum -> m Checksum
forall a b. (a -> b) -> a -> b
$ do
    let checksumType' :: CUInt
checksumType' = (Int -> CUInt
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Int -> CUInt) -> (ChecksumType -> Int) -> ChecksumType -> CUInt
forall b c a. (b -> c) -> (a -> b) -> a -> c
. ChecksumType -> Int
forall a. Enum a => a -> Int
fromEnum) ChecksumType
checksumType
    Ptr Checksum
result <- CUInt -> IO (Ptr Checksum)
g_checksum_new CUInt
checksumType'
    Text -> Ptr Checksum -> IO ()
forall a. HasCallStack => Text -> Ptr a -> IO ()
checkUnexpectedReturnNULL "checksumNew" Ptr Checksum
result
    Checksum
result' <- ((ManagedPtr Checksum -> Checksum) -> Ptr Checksum -> IO Checksum
forall a.
(HasCallStack, BoxedObject a) =>
(ManagedPtr a -> a) -> Ptr a -> IO a
wrapBoxed ManagedPtr Checksum -> Checksum
Checksum) Ptr Checksum
result
    Checksum -> IO Checksum
forall (m :: * -> *) a. Monad m => a -> m a
return Checksum
result'

#if ENABLE_OVERLOADING
#endif

-- method Checksum::copy
-- method type : OrdinaryMethod
-- Args : [Arg {argCName = "checksum", argType = TInterface (Name {namespace = "GLib", name = "Checksum"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "the #GChecksum to copy", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- Lengths : []
-- returnType : Just (TInterface (Name {namespace = "GLib", name = "Checksum"}))
-- throws : False
-- Skip return : False

foreign import ccall "g_checksum_copy" g_checksum_copy :: 
    Ptr Checksum ->                         -- checksum : TInterface (Name {namespace = "GLib", name = "Checksum"})
    IO (Ptr Checksum)

{- |
Copies a 'GI.GLib.Structs.Checksum.Checksum'. If /@checksum@/ has been closed, by calling
'GI.GLib.Structs.Checksum.checksumGetString' or @/g_checksum_get_digest()/@, the copied
checksum will be closed as well.

/Since: 2.16/
-}
checksumCopy ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    Checksum
    {- ^ /@checksum@/: the 'GI.GLib.Structs.Checksum.Checksum' to copy -}
    -> m Checksum
    {- ^ __Returns:__ the copy of the passed 'GI.GLib.Structs.Checksum.Checksum'. Use 'GI.GLib.Structs.Checksum.checksumFree'
  when finished using it. -}
checksumCopy :: Checksum -> m Checksum
checksumCopy checksum :: Checksum
checksum = IO Checksum -> m Checksum
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO Checksum -> m Checksum) -> IO Checksum -> m Checksum
forall a b. (a -> b) -> a -> b
$ do
    Ptr Checksum
checksum' <- Checksum -> IO (Ptr Checksum)
forall a. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr a)
unsafeManagedPtrGetPtr Checksum
checksum
    Ptr Checksum
result <- Ptr Checksum -> IO (Ptr Checksum)
g_checksum_copy Ptr Checksum
checksum'
    Text -> Ptr Checksum -> IO ()
forall a. HasCallStack => Text -> Ptr a -> IO ()
checkUnexpectedReturnNULL "checksumCopy" Ptr Checksum
result
    Checksum
result' <- ((ManagedPtr Checksum -> Checksum) -> Ptr Checksum -> IO Checksum
forall a.
(HasCallStack, BoxedObject a) =>
(ManagedPtr a -> a) -> Ptr a -> IO a
wrapBoxed ManagedPtr Checksum -> Checksum
Checksum) Ptr Checksum
result
    Checksum -> IO ()
forall a. ManagedPtrNewtype a => a -> IO ()
touchManagedPtr Checksum
checksum
    Checksum -> IO Checksum
forall (m :: * -> *) a. Monad m => a -> m a
return Checksum
result'

#if ENABLE_OVERLOADING
data ChecksumCopyMethodInfo
instance (signature ~ (m Checksum), MonadIO m) => O.MethodInfo ChecksumCopyMethodInfo Checksum signature where
    overloadedMethod _ = checksumCopy

#endif

-- method Checksum::free
-- method type : OrdinaryMethod
-- Args : [Arg {argCName = "checksum", argType = TInterface (Name {namespace = "GLib", name = "Checksum"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "a #GChecksum", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- Lengths : []
-- returnType : Nothing
-- throws : False
-- Skip return : False

foreign import ccall "g_checksum_free" g_checksum_free :: 
    Ptr Checksum ->                         -- checksum : TInterface (Name {namespace = "GLib", name = "Checksum"})
    IO ()

{- |
Frees the memory allocated for /@checksum@/.

/Since: 2.16/
-}
checksumFree ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    Checksum
    {- ^ /@checksum@/: a 'GI.GLib.Structs.Checksum.Checksum' -}
    -> m ()
checksumFree :: Checksum -> m ()
checksumFree checksum :: Checksum
checksum = IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ do
    Ptr Checksum
checksum' <- Checksum -> IO (Ptr Checksum)
forall a. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr a)
unsafeManagedPtrGetPtr Checksum
checksum
    Ptr Checksum -> IO ()
g_checksum_free Ptr Checksum
checksum'
    Checksum -> IO ()
forall a. ManagedPtrNewtype a => a -> IO ()
touchManagedPtr Checksum
checksum
    () -> IO ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()

#if ENABLE_OVERLOADING
data ChecksumFreeMethodInfo
instance (signature ~ (m ()), MonadIO m) => O.MethodInfo ChecksumFreeMethodInfo Checksum signature where
    overloadedMethod _ = checksumFree

#endif

-- method Checksum::get_string
-- method type : OrdinaryMethod
-- Args : [Arg {argCName = "checksum", argType = TInterface (Name {namespace = "GLib", name = "Checksum"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "a #GChecksum", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- Lengths : []
-- returnType : Just (TBasicType TUTF8)
-- throws : False
-- Skip return : False

foreign import ccall "g_checksum_get_string" g_checksum_get_string :: 
    Ptr Checksum ->                         -- checksum : TInterface (Name {namespace = "GLib", name = "Checksum"})
    IO CString

{- |
Gets the digest as a hexadecimal string.

Once this function has been called the 'GI.GLib.Structs.Checksum.Checksum' can no longer be
updated with 'GI.GLib.Structs.Checksum.checksumUpdate'.

The hexadecimal characters will be lower case.

/Since: 2.16/
-}
checksumGetString ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    Checksum
    {- ^ /@checksum@/: a 'GI.GLib.Structs.Checksum.Checksum' -}
    -> m T.Text
    {- ^ __Returns:__ the hexadecimal representation of the checksum. The
  returned string is owned by the checksum and should not be modified
  or freed. -}
checksumGetString :: Checksum -> m Text
checksumGetString checksum :: Checksum
checksum = IO Text -> m Text
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO Text -> m Text) -> IO Text -> m Text
forall a b. (a -> b) -> a -> b
$ do
    Ptr Checksum
checksum' <- Checksum -> IO (Ptr Checksum)
forall a. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr a)
unsafeManagedPtrGetPtr Checksum
checksum
    CString
result <- Ptr Checksum -> IO CString
g_checksum_get_string Ptr Checksum
checksum'
    Text -> CString -> IO ()
forall a. HasCallStack => Text -> Ptr a -> IO ()
checkUnexpectedReturnNULL "checksumGetString" CString
result
    Text
result' <- HasCallStack => CString -> IO Text
CString -> IO Text
cstringToText CString
result
    Checksum -> IO ()
forall a. ManagedPtrNewtype a => a -> IO ()
touchManagedPtr Checksum
checksum
    Text -> IO Text
forall (m :: * -> *) a. Monad m => a -> m a
return Text
result'

#if ENABLE_OVERLOADING
data ChecksumGetStringMethodInfo
instance (signature ~ (m T.Text), MonadIO m) => O.MethodInfo ChecksumGetStringMethodInfo Checksum signature where
    overloadedMethod _ = checksumGetString

#endif

-- method Checksum::reset
-- method type : OrdinaryMethod
-- Args : [Arg {argCName = "checksum", argType = TInterface (Name {namespace = "GLib", name = "Checksum"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "the #GChecksum to reset", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- Lengths : []
-- returnType : Nothing
-- throws : False
-- Skip return : False

foreign import ccall "g_checksum_reset" g_checksum_reset :: 
    Ptr Checksum ->                         -- checksum : TInterface (Name {namespace = "GLib", name = "Checksum"})
    IO ()

{- |
Resets the state of the /@checksum@/ back to its initial state.

/Since: 2.18/
-}
checksumReset ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    Checksum
    {- ^ /@checksum@/: the 'GI.GLib.Structs.Checksum.Checksum' to reset -}
    -> m ()
checksumReset :: Checksum -> m ()
checksumReset checksum :: Checksum
checksum = IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ do
    Ptr Checksum
checksum' <- Checksum -> IO (Ptr Checksum)
forall a. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr a)
unsafeManagedPtrGetPtr Checksum
checksum
    Ptr Checksum -> IO ()
g_checksum_reset Ptr Checksum
checksum'
    Checksum -> IO ()
forall a. ManagedPtrNewtype a => a -> IO ()
touchManagedPtr Checksum
checksum
    () -> IO ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()

#if ENABLE_OVERLOADING
data ChecksumResetMethodInfo
instance (signature ~ (m ()), MonadIO m) => O.MethodInfo ChecksumResetMethodInfo Checksum signature where
    overloadedMethod _ = checksumReset

#endif

-- method Checksum::update
-- method type : OrdinaryMethod
-- Args : [Arg {argCName = "checksum", argType = TInterface (Name {namespace = "GLib", name = "Checksum"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "a #GChecksum", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing},Arg {argCName = "data", argType = TCArray False (-1) 2 (TBasicType TUInt8), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "buffer used to compute the checksum", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing},Arg {argCName = "length", argType = TBasicType TInt64, direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "size of the buffer, or -1 if it is a null-terminated string.", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- Lengths : [Arg {argCName = "length", argType = TBasicType TInt64, direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "size of the buffer, or -1 if it is a null-terminated string.", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- returnType : Nothing
-- throws : False
-- Skip return : False

foreign import ccall "g_checksum_update" g_checksum_update :: 
    Ptr Checksum ->                         -- checksum : TInterface (Name {namespace = "GLib", name = "Checksum"})
    Ptr Word8 ->                            -- data : TCArray False (-1) 2 (TBasicType TUInt8)
    Int64 ->                                -- length : TBasicType TInt64
    IO ()

{- |
Feeds /@data@/ into an existing 'GI.GLib.Structs.Checksum.Checksum'. The checksum must still be
open, that is 'GI.GLib.Structs.Checksum.checksumGetString' or @/g_checksum_get_digest()/@ must
not have been called on /@checksum@/.

/Since: 2.16/
-}
checksumUpdate ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    Checksum
    {- ^ /@checksum@/: a 'GI.GLib.Structs.Checksum.Checksum' -}
    -> ByteString
    {- ^ /@data@/: buffer used to compute the checksum -}
    -> m ()
checksumUpdate :: Checksum -> ByteString -> m ()
checksumUpdate checksum :: Checksum
checksum data_ :: ByteString
data_ = IO () -> m ()
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO () -> m ()) -> IO () -> m ()
forall a b. (a -> b) -> a -> b
$ do
    let length_ :: Int64
length_ = Int -> Int64
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Int -> Int64) -> Int -> Int64
forall a b. (a -> b) -> a -> b
$ ByteString -> Int
B.length ByteString
data_
    Ptr Checksum
checksum' <- Checksum -> IO (Ptr Checksum)
forall a. (HasCallStack, ManagedPtrNewtype a) => a -> IO (Ptr a)
unsafeManagedPtrGetPtr Checksum
checksum
    Ptr Word8
data_' <- ByteString -> IO (Ptr Word8)
packByteString ByteString
data_
    Ptr Checksum -> Ptr Word8 -> Int64 -> IO ()
g_checksum_update Ptr Checksum
checksum' Ptr Word8
data_' Int64
length_
    Checksum -> IO ()
forall a. ManagedPtrNewtype a => a -> IO ()
touchManagedPtr Checksum
checksum
    Ptr Word8 -> IO ()
forall a. Ptr a -> IO ()
freeMem Ptr Word8
data_'
    () -> IO ()
forall (m :: * -> *) a. Monad m => a -> m a
return ()

#if ENABLE_OVERLOADING
data ChecksumUpdateMethodInfo
instance (signature ~ (ByteString -> m ()), MonadIO m) => O.MethodInfo ChecksumUpdateMethodInfo Checksum signature where
    overloadedMethod _ = checksumUpdate

#endif

-- method Checksum::type_get_length
-- method type : MemberFunction
-- Args : [Arg {argCName = "checksum_type", argType = TInterface (Name {namespace = "GLib", name = "ChecksumType"}), direction = DirectionIn, mayBeNull = False, argDoc = Documentation {rawDocText = Just "a #GChecksumType", sinceVersion = Nothing}, argScope = ScopeTypeInvalid, argClosure = -1, argDestroy = -1, argCallerAllocates = False, transfer = TransferNothing}]
-- Lengths : []
-- returnType : Just (TBasicType TInt64)
-- throws : False
-- Skip return : False

foreign import ccall "g_checksum_type_get_length" g_checksum_type_get_length :: 
    CUInt ->                                -- checksum_type : TInterface (Name {namespace = "GLib", name = "ChecksumType"})
    IO Int64

{- |
Gets the length in bytes of digests of type /@checksumType@/

/Since: 2.16/
-}
checksumTypeGetLength ::
    (B.CallStack.HasCallStack, MonadIO m) =>
    GLib.Enums.ChecksumType
    {- ^ /@checksumType@/: a 'GI.GLib.Enums.ChecksumType' -}
    -> m Int64
    {- ^ __Returns:__ the checksum length, or -1 if /@checksumType@/ is
not supported. -}
checksumTypeGetLength :: ChecksumType -> m Int64
checksumTypeGetLength checksumType :: ChecksumType
checksumType = IO Int64 -> m Int64
forall (m :: * -> *) a. MonadIO m => IO a -> m a
liftIO (IO Int64 -> m Int64) -> IO Int64 -> m Int64
forall a b. (a -> b) -> a -> b
$ do
    let checksumType' :: CUInt
checksumType' = (Int -> CUInt
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Int -> CUInt) -> (ChecksumType -> Int) -> ChecksumType -> CUInt
forall b c a. (b -> c) -> (a -> b) -> a -> c
. ChecksumType -> Int
forall a. Enum a => a -> Int
fromEnum) ChecksumType
checksumType
    Int64
result <- CUInt -> IO Int64
g_checksum_type_get_length CUInt
checksumType'
    Int64 -> IO Int64
forall (m :: * -> *) a. Monad m => a -> m a
return Int64
result

#if ENABLE_OVERLOADING
#endif

#if ENABLE_OVERLOADING
type family ResolveChecksumMethod (t :: Symbol) (o :: *) :: * where
    ResolveChecksumMethod "copy" o = ChecksumCopyMethodInfo
    ResolveChecksumMethod "free" o = ChecksumFreeMethodInfo
    ResolveChecksumMethod "reset" o = ChecksumResetMethodInfo
    ResolveChecksumMethod "update" o = ChecksumUpdateMethodInfo
    ResolveChecksumMethod "getString" o = ChecksumGetStringMethodInfo
    ResolveChecksumMethod l o = O.MethodResolutionFailed l o

instance (info ~ ResolveChecksumMethod t Checksum, O.MethodInfo info Checksum p) => O.IsLabelProxy t (Checksum -> p) where
    fromLabelProxy _ = O.overloadedMethod (O.MethodProxy :: O.MethodProxy info)

#if MIN_VERSION_base(4,9,0)
instance (info ~ ResolveChecksumMethod t Checksum, O.MethodInfo info Checksum p) => O.IsLabel t (Checksum -> p) where
#if MIN_VERSION_base(4,10,0)
    fromLabel = O.overloadedMethod (O.MethodProxy :: O.MethodProxy info)
#else
    fromLabel _ = O.overloadedMethod (O.MethodProxy :: O.MethodProxy info)
#endif
#endif

#endif