pub trait DebugToJson {
// Required method
fn fmt(&self, out: &mut Formatter<'_>) -> Result;
// Provided method
fn to_json_string(&self) -> String
where Self: Sized { ... }
}Expand description
Trait that can be automatically derived for structs and enums. When it’s derived, a Debug implementation is also added,
so the object can be printed with println!.
Example:
use nop_json::DebugToJson;
#[derive(DebugToJson)]
struct Point {x: i32, y: i32}
let point = Point {x: 1, y: 2};
println!("{:?}", point);Here is what automatic implementation expands to. If you write:
use nop_json::DebugToJson;
#[derive(DebugToJson)]
struct Point {x: i32, y: i32}The implementation will be:
use nop_json::DebugToJson;
struct Point {x: i32, y: i32}
impl DebugToJson for Point
{ fn fmt(&self, out: &mut std::fmt::Formatter) -> std::fmt::Result
{ write!(out, "{{\"x\":")?;
DebugToJson::fmt(&self.x, out)?;
write!(out, ",\"y\":")?;
DebugToJson::fmt(&self.y, out)?;
write!(out, "}}")
}
}
impl std::fmt::Debug for Point
{ fn fmt(&self, out: &mut std::fmt::Formatter) -> std::fmt::Result
{ DebugToJson::fmt(self, out)
}
}For more information, see main page.
Required Methods§
Provided Methods§
Sourcefn to_json_string(&self) -> Stringwhere
Self: Sized,
fn to_json_string(&self) -> Stringwhere
Self: Sized,
Any type that implements DebugToJson can be converted to JSON string. For example DebugToJson is implemented for primitive types:
use nop_json::DebugToJson;
let smth = true;
assert_eq!(smth.to_json_string(), "true".to_string());For custom types:
use nop_json::DebugToJson;
#[derive(DebugToJson)]
struct Something {value: i32}
let smth = Something {value: 123};
assert_eq!(smth.to_json_string(), "{\"value\":123}".to_string());