Struct conch_runtime::env::VarRestorer

pub struct VarRestorer<E: ?Sized> where
    E: VariableEnvironment,  { /* fields omitted */ }

Maintains a state of all variable definitions that have been modified so that they can be restored later.

Note: the caller should take care that a restorer instance is always called with the same environment for its entire lifetime. Using different environments with the same restorer instance will undoubtedly do the wrong thing eventually, and no guarantees can be made.

Methods

impl<E: ?Sized> VarRestorer<E> where
    E: VariableEnvironment, 

fn new() -> Self

Create a new wrapper.

fn with_capacity(capacity: usize) -> Self

Create a new wrapper and reserve capacity for backing up the previous file descriptors of the environment.

fn restore(self, env: &mut E) where
    E: ExportedVariableEnvironment + UnsetVariableEnvironment, 

Deprecated

: use the VarEnvRestorer trait instead

Restore all variable definitions to their original state.

impl<E: ?Sized> VarRestorer<E> where
    E: ExportedVariableEnvironment,
    E::VarName: Clone,
    E::Var: Clone, 

fn set_exported_var(
    &mut self,
    name: E::VarName,
    val: E::Var,
    exported: bool,
    env: &mut E
)

Deprecated

: use the VarEnvRestorer trait instead

Backup and set the value of some variable, maintaining its status as an environment variable if previously set as such.

fn unset_var(&mut self, name: E::VarName, env: &mut E) where
    E: UnsetVariableEnvironment, 

Deprecated

: use the VarEnvRestorer trait instead

Backup and unset the value of some variable (including environment variables).

fn backup(&mut self, key: E::VarName, env: &E)

Deprecated

: use the VarEnvRestorer trait instead

Backs up the original value of specified variable.

The original value of the variable is the one the environment held before it was passed into this wrapper. That is, if a variable is backed up multiple times, only the value before the first call could be restored later.

Trait Implementations

impl<E: Clone + ?Sized> Clone for VarRestorer<E> where
    E: VariableEnvironment,
    E::VarName: Clone,
    E::Var: Clone, 

fn clone(&self) -> VarRestorer<E>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<E: ?Sized> Eq for VarRestorer<E> where
    E: VariableEnvironment,
    E::VarName: Eq,
    E::Var: Eq, 

impl<E: ?Sized> PartialEq<Self> for VarRestorer<E> where
    E: VariableEnvironment,
    E::VarName: Eq,
    E::Var: Eq, 

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl<E: ?Sized> Debug for VarRestorer<E> where
    E: VariableEnvironment,
    E::VarName: Debug,
    E::Var: Debug, 

fn fmt(&self, fmt: &mut Formatter) -> Result

Formats the value using the given formatter.

impl<E: ?Sized> Default for VarRestorer<E> where
    E: VariableEnvironment, 

fn default() -> Self

Returns the "default value" for a type.

impl<E: ?Sized> VarEnvRestorer<E> for VarRestorer<E> where
    E: ExportedVariableEnvironment + UnsetVariableEnvironment,
    E::VarName: Clone,
    E::Var: Clone, 

fn reserve(&mut self, additional: usize)

Reserves capacity for at least additional more variables to be backed up.

fn set_exported_var(
    &mut self,
    name: E::VarName,
    val: E::Var,
    exported: bool,
    env: &mut E
)

Deprecated

: Use VarEnvRestorer2::set_exported_var2 instead

Backup and set the value of some variable (and its exported status).

fn unset_var(&mut self, name: E::VarName, env: &mut E)

Backup and unset the value of some variable (including environment variables).

fn backup(&mut self, key: E::VarName, env: &E)

Backs up the original value of specified variable.

fn restore(&mut self, env: &mut E)

Restore all variable definitions to their original state.

impl<E: ?Sized> VarEnvRestorer2<E> for VarRestorer<E> where
    E: ExportedVariableEnvironment + UnsetVariableEnvironment,
    E::VarName: Clone,
    E::Var: Clone, 

fn set_exported_var2(
    &mut self,
    name: E::VarName,
    val: E::Var,
    exported: Option<bool>,
    env: &mut E
)

Backup and set the value of some variable, either explicitly setting its exported status as specified, or maintaining its status as an environment variable if previously set as such.