Enum tristate::TriState
[−]
[src]
pub enum TriState { Yes, No, Unknown, }
A three-valued type equivalent to Option<bool>
.
Variants
Yes
The tri-state value signifying definitive truth.
No
The tri-state value signifying definitive falsity.
Unknown
The tri-state value signifying an unknown truth value.
Methods
impl TriState
[src]
fn yes(self) -> bool
Is self
equal to Yes
?
fn no(self) -> bool
Is self
equal to No
?
fn unknown(self) -> bool
Is self
equal to Unknown
?
fn definitely(self) -> bool
A mnemonic for yes()
.
fn definitely_not(self) -> bool
A mnemonic for no()
.
fn maybe(self) -> bool
A mnemonic for unknown()
.
fn to_bool(self) -> Option<bool>
Converts self
to an Option<bool>
. Equivalent to Option::<bool>::from(self)
.
Trait Implementations
impl Clone for TriState
[src]
fn clone(&self) -> TriState
Returns a copy of the value. Read more
fn clone_from(&mut self, source: &Self)
1.0.0
Performs copy-assignment from source
. Read more
impl Copy for TriState
[src]
impl Eq for TriState
[src]
impl PartialEq for TriState
[src]
fn eq(&self, __arg_0: &TriState) -> bool
This method tests for self
and other
values to be equal, and is used by ==
. Read more
fn ne(&self, other: &Rhs) -> bool
1.0.0
This method tests for !=
.
impl Ord for TriState
[src]
fn cmp(&self, __arg_0: &TriState) -> Ordering
This method returns an Ordering
between self
and other
. Read more
impl PartialOrd for TriState
[src]
fn partial_cmp(&self, __arg_0: &TriState) -> Option<Ordering>
This method returns an ordering between self
and other
values if one exists. Read more
fn lt(&self, other: &Rhs) -> bool
1.0.0
This method tests less than (for self
and other
) and is used by the <
operator. Read more
fn le(&self, other: &Rhs) -> bool
1.0.0
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
fn gt(&self, other: &Rhs) -> bool
1.0.0
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
fn ge(&self, other: &Rhs) -> bool
1.0.0
This method tests greater than or equal to (for self
and other
) and is used by the >=
operator. Read more