More robust and versatile implementation of derive(Debug) and derive(Display). Unlike the version ofderive(Debug) in the standard library, these macros will always successfully generate an implementation - even if a member does not implement Debug/Display. In that case, the generated implementation will print a replacement string of the form <TypeName>.

``rust use fmt_derive::Debug; // replacement foruse std::fmt::Debug;`

// a type that implements neither Debug nor Display struct Unprintable;

[derive(Debug, crate::Display)]

struct Printable { // unprintable members will be printed as <Type> unprintable: Unprintable,

// use `#[display(ignore)]` (or `#[debug(ignore]` respectively) to skip a member when printing
#[display(ignore)]
ignored: u32,

// use the `fmt` attribute to refer to both `Debug` and `Display` at once
#[fmt("{:#08X}", self.hex_number)]
hex_number: u32,

}

fn main() { let printable = Printable{ hex_number: 0xDEADBEEF, ignored: 42, unprintable: Unprintable, };

assert_eq!(format!("{:?}", printable), "Printable { unprintable: <Unprintable>, ignored: 42, hex_number: 0xDEADBEEF }");
assert_eq!(format!("{}", printable), "Printable { unprintable: <Unprintable>, hex_number: 0xDEADBEEF }");

} ```

no_std

This crate is no_std and can be used from both no_std and std contexts without any action required.

MSRV

The current MSRV is 1.56.0.