Make the Context trait unimplementable

This commit is contained in:
Elichai Turkel 2019-11-27 17:36:06 +02:00
parent 5de62f80f3
commit fe688ada65
No known key found for this signature in database
GPG Key ID: 9383CDE9E8E66A7F
1 changed files with 18 additions and 2 deletions

View File

@ -8,8 +8,8 @@ use Secp256k1;
pub use self::std_only::*;
/// A trait for all kinds of Context's that Lets you define the exact flags and a function to deallocate memory.
/// * DO NOT * implement it for your own types.
pub unsafe trait Context {
/// It shouldn't be possible to implement this for types outside this crate.
pub unsafe trait Context : private::Sealed {
/// Flags for the ffi.
const FLAGS: c_uint;
/// A constant description of the context.
@ -39,8 +39,24 @@ pub struct AllPreallocated<'buf> {
phantom: PhantomData<&'buf ()>,
}
mod private {
use super::*;
// A trick to prevent users from implementing a trait.
// on one hand this trait is public, on the other it's in a private module
// so it's not visible to anyone besides it's parent (the context module)
pub trait Sealed {}
impl<'buf> Sealed for AllPreallocated<'buf> {}
impl<'buf> Sealed for VerifyOnlyPreallocated<'buf> {}
impl<'buf> Sealed for SignOnlyPreallocated<'buf> {}
}
#[cfg(feature = "std")]
mod std_only {
impl private::Sealed for SignOnly {}
impl private::Sealed for All {}
impl private::Sealed for VerifyOnly {}
use super::*;
/// Represents the set of capabilities needed for signing.