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use super::*;
use core::mem::transmute_copy;
use core::mem::zeroed;
/// Provides automatic parameter conversion in cases where the Windows API expects implicit conversion support.
///
/// There is no need to implement this trait. Blanket implementations are provided for all applicable Windows types.
pub trait Param<T: TypeKind, C = <T as TypeKind>::TypeKind>: Sized
where
T: Type<T>,
{
#[doc(hidden)]
unsafe fn param(self) -> ParamValue<T>;
}
impl<T> Param<T> for Option<&T>
where
T: Type<T>,
{
unsafe fn param(self) -> ParamValue<T> {
ParamValue::Borrowed(match self {
Some(item) => transmute_copy(item),
None => zeroed(),
})
}
}
impl<T, U> Param<T, InterfaceType> for &U
where
T: TypeKind<TypeKind = InterfaceType> + Clone,
T: Interface,
U: Interface,
U: imp::CanInto<T>,
{
unsafe fn param(self) -> ParamValue<T> {
if U::QUERY {
self.cast()
.map_or(ParamValue::Borrowed(zeroed()), |ok| ParamValue::Owned(ok))
} else {
ParamValue::Borrowed(transmute_copy(self))
}
}
}
impl<T> Param<T, CloneType> for &T
where
T: TypeKind<TypeKind = CloneType> + Clone,
{
unsafe fn param(self) -> ParamValue<T> {
ParamValue::Borrowed(transmute_copy(self))
}
}
impl<T, U> Param<T, CopyType> for U
where
T: TypeKind<TypeKind = CopyType> + Clone,
U: TypeKind<TypeKind = CopyType> + Clone,
U: imp::CanInto<T>,
{
unsafe fn param(self) -> ParamValue<T> {
ParamValue::Owned(transmute_copy(&self))
}
}