Struct Fmt

pub struct Fmt;

🌐 A string formatting namespace.

See also the std::fmt module.

Implementations

impl Fmt

pub fn format(args: FmtArguments<'_>) -> String

Available on crate feature alloc only.

Takes an FmtArguments struct and returns the resulting formatted string.

The FmtArguments instance can be created with the format_args! macro.

See alloc::fmt::format.

pub fn format_buf<'a>( buf: &'a mut [u8], args: FmtArguments<'_>, ) -> Result<&'a str, &'a str>

Writes formatted output into the given byte buffer.

Returns:

• Ok(&str) if all the formatted data fits into buf.
• Err(&str) containing the valid partial result if truncation occurred.

Example

let mut buf = [0u8; 32]; // Big enough to fit everything
let s = Fmt::format_buf(&mut buf, format_args!["Test: {} {}", "foo", 42]);
assert_eq!(Ok("Test: foo 42"), s);

let mut buf = [0u8; 9]; // Can't fit everything
let s = Fmt::format_buf(&mut buf, format_args!["Test: {} {}", "foo", 42]);
assert_eq!(Err("Test: foo"), s);

pub fn write( output: &mut dyn FmtWrite, args: FmtArguments<'_>, ) -> Result<(), FmtError>

Takes an output stream and an FmtArguments struct that can be precompiled with the format_args! macro.

The arguments will be formatted according to the specified format string into the output stream provided.

See core::fmt::write.