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Diffstat (limited to 'vendor/bitflags/examples/fmt.rs')
-rw-r--r-- | vendor/bitflags/examples/fmt.rs | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/vendor/bitflags/examples/fmt.rs b/vendor/bitflags/examples/fmt.rs new file mode 100644 index 0000000..724b207 --- /dev/null +++ b/vendor/bitflags/examples/fmt.rs @@ -0,0 +1,49 @@ +//! An example of implementing Rust's standard formatting and parsing traits for flags types. + +use core::{fmt, str}; + +bitflags::bitflags! { + // You can `#[derive]` the `Debug` trait, but implementing it manually + // can produce output like `A | B` instead of `Flags(A | B)`. + // #[derive(Debug)] + #[derive(PartialEq, Eq)] + pub struct Flags: u32 { + const A = 1; + const B = 2; + const C = 4; + const D = 8; + } +} + +impl fmt::Debug for Flags { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + bitflags::parser::to_writer(self, f) + } +} + +impl fmt::Display for Flags { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + bitflags::parser::to_writer(self, f) + } +} + +impl str::FromStr for Flags { + type Err = bitflags::parser::ParseError; + + fn from_str(flags: &str) -> Result<Self, Self::Err> { + bitflags::parser::from_str(flags) + } +} + +fn main() -> Result<(), bitflags::parser::ParseError> { + let flags = Flags::A | Flags::B; + + println!("{}", flags); + + let formatted = flags.to_string(); + let parsed: Flags = formatted.parse()?; + + assert_eq!(flags, parsed); + + Ok(()) +} |