# partialdebug
[
](https://github.com/dimpolo/partialdebug)
[
](https://crates.io/crates/partialdebug)
[
](https://docs.rs/partialdebug)
Derive Debug for types where not all fields implement Debug.
This crate works on stable and with `no_std`.
On nightly the `unstable` feature can be used for specialization based trait detection and/or `..` formatting.
#### Placeholder with Type Info
```rust
use partialdebug::placeholder::PartialDebug;
#[derive(PartialDebug)]
struct Dog {
legs: usize,
eyes: usize,
dna: DNA,
}
assert_eq!(format!("{:?}", Dog::new()), "Dog { legs: 4, eyes: 2, dna: DNA }");
```
#### Placeholder with Custom Text
```rust
use partialdebug::placeholder::PartialDebug;
#[derive(PartialDebug)]
#[debug_placeholder = "Unknown"]
struct Dog {
legs: usize,
eyes: usize,
dna: DNA,
}
assert_eq!(format!("{:?}", Dog::new()), "Dog { legs: 4, eyes: 2, dna: Unknown }");
```
#### Non Exhaustive
Only available on nightly after setting the `unstable` feature.
Requires the `debug_non_exhaustive` feature to be enabled in user code.
Only available for structs with named fields.
```rust
#![feature(debug_non_exhaustive)]
use partialdebug::non_exhaustive::PartialDebug;
#[derive(PartialDebug)]
struct Dog {
legs: usize,
eyes: usize,
dna: DNA,
}
assert_eq!(format!("{:?}", Dog::new()), "Dog { legs: 4, eyes: 2, .. }");
```
#### Caveats
Trait detection for generic types requires specialization.
To enable specialization based trait detection use a nightly compiler and enable the `unstable` feature.
```rust
use partialdebug::placeholder::PartialDebug;
#[derive(PartialDebug)]
struct Container(T);
#[cfg(feature = "unstable")]
assert_eq!(format!("{:?}", Container(42)), "Container(42)");
#[cfg(not(feature = "unstable"))]
assert_eq!(format!("{:?}", Container(42)), "Container(T)");
```
#### License
Licensed under either of Apache License, Version
2.0 or MIT license at your option.
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
be dual licensed as above, without any additional terms or conditions.