Struct alloc::fmt::DebugStruct

#[must_use = "must eventually call `finish()` on Debug builders"]
pub struct DebugStruct<'a, 'b> where
    'b: 'a,  { /* fields omitted */ }

A struct to help with fmt::Debug implementations.

This is useful when you wish to output a formatted struct as a part of your Debug::fmt implementation.

This can be constructed by the Formatter::debug_struct method.

Examples

use std::fmt;

struct Foo {
    bar: i32,
    baz: String,
}

impl fmt::Debug for Foo {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.debug_struct("Foo")
           .field("bar", &self.bar)
           .field("baz", &self.baz)
           .finish()
    }
}

// prints "Foo { bar: 10, baz: "Hello World" }"
println!("{:?}", Foo { bar: 10, baz: "Hello World".to_string() });

Methods

impl<'a, 'b> DebugStruct<'a, 'b> where     'b: 'a,

pub fn field(&mut self, name: &str, value: &Debug) -> &mut DebugStruct<'a, 'b>

Adds a new field to the generated struct output.

pub fn finish(&mut self) -> Result<(), Error>

Finishes output and returns any error encountered.