{- | Copyright : Will Thompson, Iñaki García Etxebarria and Jonas Platte License : LGPL-2.1 Maintainer : Iñaki García Etxebarria (garetxe@gmail.com) -} module GI.GLib.Unions.DoubleIEEE754 ( -- * Exported types DoubleIEEE754(..) , newZeroDoubleIEEE754 , noDoubleIEEE754 , -- * Properties -- ** VDouble doubleIEEE754ReadVDouble , ) where import Prelude () import Data.GI.Base.ShortPrelude import qualified Data.Text as T import qualified Data.ByteString.Char8 as B import qualified Data.Map as Map import GI.GLib.Types import GI.GLib.Callbacks newtype DoubleIEEE754 = DoubleIEEE754 (ForeignPtr DoubleIEEE754) -- | Construct a `DoubleIEEE754` struct initialized to zero. newZeroDoubleIEEE754 :: MonadIO m => m DoubleIEEE754 newZeroDoubleIEEE754 = liftIO $ callocBytes 8 >>= wrapPtr DoubleIEEE754 noDoubleIEEE754 :: Maybe DoubleIEEE754 noDoubleIEEE754 = Nothing doubleIEEE754ReadVDouble :: DoubleIEEE754 -> IO Double doubleIEEE754ReadVDouble s = withManagedPtr s $ \ptr -> do val <- peek (ptr `plusPtr` 0) :: IO CDouble let val' = realToFrac val return val' type family ResolveDoubleIEEE754Method (t :: Symbol) (o :: *) :: * where ResolveDoubleIEEE754Method l o = MethodResolutionFailed l o instance (info ~ ResolveDoubleIEEE754Method t DoubleIEEE754, MethodInfo info DoubleIEEE754 p) => IsLabelProxy t (DoubleIEEE754 -> p) where fromLabelProxy _ = overloadedMethod (MethodProxy :: MethodProxy info) #if MIN_VERSION_base(4,9,0) instance (info ~ ResolveDoubleIEEE754Method t DoubleIEEE754, MethodInfo info DoubleIEEE754 p) => IsLabel t (DoubleIEEE754 -> p) where fromLabel _ = overloadedMethod (MethodProxy :: MethodProxy info) #endif