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// revisions: full min
#![cfg_attr(full, feature(const_generics))]
#![cfg_attr(full, allow(incomplete_features))]
struct PhantomU8<const X: u8>;
trait FxpStorage {
type SInt; // Add arithmetic traits as needed.
}
macro_rules! fxp_storage_impls {
($($($n:literal)|+ => $sint:ty),* $(,)?) => {
$($(impl FxpStorage for PhantomU8<$n> {
type SInt = $sint;
})*)*
}
}
fxp_storage_impls! {
1 => i8,
2 => i16,
3 | 4 => i32,
5 | 6 | 7 | 8 => i64,
9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 => i128,
}
type FxpStorageHelper<const INT_BITS: u8, const FRAC_BITS: u8> =
PhantomU8<{(INT_BITS + FRAC_BITS + 7) / 8}>;
//[min]~^ ERROR generic parameters may not be used in const operations
//[min]~| ERROR generic parameters may not be used in const operations
struct Fxp<const INT_BITS: u8, const FRAC_BITS: u8>
where
FxpStorageHelper<INT_BITS, FRAC_BITS>: FxpStorage,
//[full]~^ ERROR constant expression depends on a generic parameter
{
storage: <FxpStorageHelper<INT_BITS, FRAC_BITS> as FxpStorage>::SInt,
}
fn main() {
Fxp::<1, 15> { storage: 0i16 };
Fxp::<2, 15> { storage: 0i32 };
}
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