pub struct Sysvar<'info, T: Sysvar> { /* private fields */ }
Expand description
Type validating that the account is a sysvar and deserializing it.
If possible, sysvars should not be used via accounts
but by using the get
function on the desired sysvar. This is because using get
does not run the risk of Anchor having a bug in its Sysvar
type
and using get
also decreases tx size, making space for other
accounts that cannot be requested via syscall.
Example
// OK - via account in the account validation struct
#[derive(Accounts)]
pub struct Example<'info> {
pub clock: Sysvar<'info, Clock>
}
// BETTER - via syscall in the instruction function
fn better(ctx: Context<Better>) -> Result<()> {
let clock = Clock::get()?;
}
Implementations
sourceimpl<'info, T: Sysvar> Sysvar<'info, T>
impl<'info, T: Sysvar> Sysvar<'info, T>
pub fn from_account_info(
acc_info: &AccountInfo<'info>
) -> Result<Sysvar<'info, T>>
Trait Implementations
sourceimpl<'info, T: Sysvar> Accounts<'info> for Sysvar<'info, T>
impl<'info, T: Sysvar> Accounts<'info> for Sysvar<'info, T>
sourcefn try_accounts(
_program_id: &Pubkey,
accounts: &mut &[AccountInfo<'info>],
_ix_data: &[u8],
_bumps: &mut BTreeMap<String, u8>,
_reallocs: &mut BTreeSet<Pubkey>
) -> Result<Self>
fn try_accounts(
_program_id: &Pubkey,
accounts: &mut &[AccountInfo<'info>],
_ix_data: &[u8],
_bumps: &mut BTreeMap<String, u8>,
_reallocs: &mut BTreeSet<Pubkey>
) -> Result<Self>
Returns the validated accounts struct. What constitutes “valid” is
program dependent. However, users of these types should never have to
worry about account substitution attacks. For example, if a program
expects a Mint
account from the SPL token program in a particular
field, then it should be impossible for this method to return Ok
if
any other account type is given–from the SPL token program or elsewhere. Read more
sourceimpl<'info, T: Sysvar> AccountsExit<'info> for Sysvar<'info, T>
impl<'info, T: Sysvar> AccountsExit<'info> for Sysvar<'info, T>
sourceimpl<'info, T: Sysvar> AsRef<AccountInfo<'info>> for Sysvar<'info, T>
impl<'info, T: Sysvar> AsRef<AccountInfo<'info>> for Sysvar<'info, T>
sourcefn as_ref(&self) -> &AccountInfo<'info>
fn as_ref(&self) -> &AccountInfo<'info>
Converts this type into a shared reference of the (usually inferred) input type.
sourceimpl<'info, T: Sysvar> ToAccountInfos<'info> for Sysvar<'info, T>
impl<'info, T: Sysvar> ToAccountInfos<'info> for Sysvar<'info, T>
fn to_account_infos(&self) -> Vec<AccountInfo<'info>>ⓘNotable traits for Vec<u8, A>impl<A> Write for Vec<u8, A> where
A: Allocator,
A: Allocator,
sourceimpl<'info, T: Sysvar> ToAccountMetas for Sysvar<'info, T>
impl<'info, T: Sysvar> ToAccountMetas for Sysvar<'info, T>
sourcefn to_account_metas(&self, _is_signer: Option<bool>) -> Vec<AccountMeta>ⓘNotable traits for Vec<u8, A>impl<A> Write for Vec<u8, A> where
A: Allocator,
fn to_account_metas(&self, _is_signer: Option<bool>) -> Vec<AccountMeta>ⓘNotable traits for Vec<u8, A>impl<A> Write for Vec<u8, A> where
A: Allocator,
A: Allocator,
is_signer
is given as an optional override for the signer meta field.
This covers the edge case when a program-derived-address needs to relay
a transaction from a client to another program but sign the transaction
before the relay. The client cannot mark the field as a signer, and so
we have to override the is_signer meta field given by the client. Read more
Auto Trait Implementations
impl<'info, T> !RefUnwindSafe for Sysvar<'info, T>
impl<'info, T> !Send for Sysvar<'info, T>
impl<'info, T> !Sync for Sysvar<'info, T>
impl<'info, T> Unpin for Sysvar<'info, T> where
T: Unpin,
impl<'info, T> !UnwindSafe for Sysvar<'info, T>
Blanket Implementations
impl<T> AbiExample for T
impl<T> AbiExample for T
default fn example() -> T
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more