1.0.0[−][src]Trait std::any::Any
A type to emulate dynamic typing.
Most types implement Any
. However, any type which contains a non-'static
reference does not.
See the module-level documentation for more details.
Required methods
Loading content...Methods
impl dyn Any + 'static
[src]
pub fn is<T>(&self) -> bool where
T: Any,
[src]
T: Any,
Returns true
if the boxed type is the same as T
.
Examples
use std::any::Any; fn is_string(s: &dyn Any) { if s.is::<String>() { println!("It's a string!"); } else { println!("Not a string..."); } } fn main() { is_string(&0); is_string(&"cookie monster".to_string()); }Run
pub fn downcast_ref<T>(&self) -> Option<&T> where
T: Any,
[src]
T: Any,
Returns some reference to the boxed value if it is of type T
, or
None
if it isn't.
Examples
use std::any::Any; fn print_if_string(s: &dyn Any) { if let Some(string) = s.downcast_ref::<String>() { println!("It's a string({}): '{}'", string.len(), string); } else { println!("Not a string..."); } } fn main() { print_if_string(&0); print_if_string(&"cookie monster".to_string()); }Run
pub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: Any,
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T: Any,
Returns some mutable reference to the boxed value if it is of type T
, or
None
if it isn't.
Examples
use std::any::Any; fn modify_if_u32(s: &mut dyn Any) { if let Some(num) = s.downcast_mut::<u32>() { *num = 42; } } fn main() { let mut x = 10u32; let mut s = "starlord".to_string(); modify_if_u32(&mut x); modify_if_u32(&mut s); assert_eq!(x, 42); assert_eq!(&s, "starlord"); }Run
impl dyn Any + 'static + Send
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pub fn is<T>(&self) -> bool where
T: Any,
[src]
T: Any,
Forwards to the method defined on the type Any
.
Examples
use std::any::Any; fn is_string(s: &(dyn Any + Send)) { if s.is::<String>() { println!("It's a string!"); } else { println!("Not a string..."); } } fn main() { is_string(&0); is_string(&"cookie monster".to_string()); }Run
pub fn downcast_ref<T>(&self) -> Option<&T> where
T: Any,
[src]
T: Any,
Forwards to the method defined on the type Any
.
Examples
use std::any::Any; fn print_if_string(s: &(dyn Any + Send)) { if let Some(string) = s.downcast_ref::<String>() { println!("It's a string({}): '{}'", string.len(), string); } else { println!("Not a string..."); } } fn main() { print_if_string(&0); print_if_string(&"cookie monster".to_string()); }Run
pub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: Any,
[src]
T: Any,
Forwards to the method defined on the type Any
.
Examples
use std::any::Any; fn modify_if_u32(s: &mut (dyn Any + Send)) { if let Some(num) = s.downcast_mut::<u32>() { *num = 42; } } fn main() { let mut x = 10u32; let mut s = "starlord".to_string(); modify_if_u32(&mut x); modify_if_u32(&mut s); assert_eq!(x, 42); assert_eq!(&s, "starlord"); }Run
impl dyn Any + 'static + Sync + Send
[src]
pub fn is<T>(&self) -> bool where
T: Any,
1.28.0[src]
T: Any,
Forwards to the method defined on the type Any
.
Examples
use std::any::Any; fn is_string(s: &(dyn Any + Send + Sync)) { if s.is::<String>() { println!("It's a string!"); } else { println!("Not a string..."); } } fn main() { is_string(&0); is_string(&"cookie monster".to_string()); }Run
pub fn downcast_ref<T>(&self) -> Option<&T> where
T: Any,
1.28.0[src]
T: Any,
Forwards to the method defined on the type Any
.
Examples
use std::any::Any; fn print_if_string(s: &(dyn Any + Send + Sync)) { if let Some(string) = s.downcast_ref::<String>() { println!("It's a string({}): '{}'", string.len(), string); } else { println!("Not a string..."); } } fn main() { print_if_string(&0); print_if_string(&"cookie monster".to_string()); }Run
pub fn downcast_mut<T>(&mut self) -> Option<&mut T> where
T: Any,
1.28.0[src]
T: Any,
Forwards to the method defined on the type Any
.
Examples
use std::any::Any; fn modify_if_u32(s: &mut (dyn Any + Send + Sync)) { if let Some(num) = s.downcast_mut::<u32>() { *num = 42; } } fn main() { let mut x = 10u32; let mut s = "starlord".to_string(); modify_if_u32(&mut x); modify_if_u32(&mut s); assert_eq!(x, 42); assert_eq!(&s, "starlord"); }Run