[−][src]Crate debug_helper
Debug Helper
This crate provides declarative macros to help you implement the Debug
trait manually.
Examples
For structs,
#[macro_use] extern crate debug_helper; use std::fmt::{self, Formatter, Debug}; pub struct A { pub f1: u8, pub f2: i16, pub f3: f64, } impl Debug for A { fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> { impl_debug_for_struct!(A, f, self, .f1, (.f3, "{:.3}", self.f3)); } } let a = A { f1: 1, f2: 2, f3: std::f64::consts::PI, }; println!("{:#?}", a); /* A { f1: 1, f3: 3.142, } */
For tuple structs,
#[macro_use] extern crate debug_helper; use std::fmt::{self, Formatter, Debug}; pub struct A(pub u8, pub i16, pub f64); impl Debug for A { fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> { impl_debug_for_tuple_struct!(A, f, self, .0, (.2, "{:.3}", self.2)); } } let a = A(1, 2, std::f64::consts::PI); println!("{:#?}", a); /* A( 1, 3.142, ) */
For enums,
#[macro_use] extern crate debug_helper; use std::fmt::{self, Formatter, Debug}; pub enum A { V1, V2(u8, i16, f64), V3 { f1: u8, f2: i16, f3: f64, }, } impl Debug for A { fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> { impl_debug_for_enum!(A::{V1, (V2(f1, _, f3): (.f1, (.f3, "{:.3}", f3))), {V3{f1, f2: _, f3}: (.f1, (.f3, "{:.3}", f3))}}, f, self); } } let a = A::V1; let b = A::V2(1, 2, std::f64::consts::PI); let c = A::V3{ f1: 1, f2: 2, f3: std::f64::consts::PI, }; println!("{:#?}", a); println!("{:#?}", b); println!("{:#?}", c); /* V1 V2( 1, 3.142, ) V3 { f1: 1, f3: 3.142, } */
You can add named fields even if they are not defined in your type,
#[macro_use] extern crate debug_helper; use std::fmt::{self, Formatter, Debug}; pub struct A { pub f1: u8, pub f2: i16, pub f3: f64, } impl Debug for A { fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), fmt::Error> { impl_debug_for_struct!(A, f, self, .f1, (.f3, "{:.3}", self.f3), (.sum, "{:.3}", self.f1 as f64 + self.f2 as f64 + self.f3)); } } let a = A { f1: 1, f2: 2, f3: std::f64::consts::PI, }; println!("{:#?}", a); /* A { f1: 1, f3: 3.142, sum: 6.142, } */
In most cases, you can use the derivative
crate to implement the Debug
trait.
Re-exports
pub extern crate alloc; |
Macros
impl_debug_for_enum | |
impl_debug_for_struct | |
impl_debug_for_tuple_struct |