# custom_debug
Derive `Debug` with a custom format per field.
# Example usage
Here is a showcase of `custom_debug`s features:
```rust
use custom_debug::Debug;
use std::fmt;
#[derive(Debug)]
struct Foo {
#[debug(format = "{} things")]
x: i32,
#[debug(skip)]
y: i32,
#[debug(with = hex_fmt)]
z: i32,
#[debug(skip_if = Option::is_none)]
label: Option<String>,
}
fn hex_fmt<T: fmt::Debug>(n: &T, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "0x{:02X?}", n)
}
```
The resulting debug output would look something like this:
```
Foo {
x: 42 things,
z: 0xAB
}
```
# Field attributes reference
Attributes within a section below are considered mutually exclusive.
## Skip attributes
| `skip` | Unconditionally skips a field. |
| `skip_if = path::to::function` | Skips a field if `path::to::function(&field)` returns `true`. |
## Format attributes
| `format = "format string {}"` | Formats a field using a format string. Must contain a placeholder (`{}`) with modifiers of your choice. |
| `with = path::to::formatter` | Formats a field using `path::to::formatter`. The required signature is `fn(&T, &mut std::fmt::Formatter) -> std::fmt::Result` where `T` is a type compatible with the field's type (i.e. the function can be generic and coercions apply). |