Struct readable::toa::DtoaTmp

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pub struct DtoaTmp { /* private fields */ }

Expand description

A short-lived version of Dtoa

This version doesn’t save the formatting computation, and is meant for cases where the lifetime of the formatted output &str is very brief.

This version has less overhead, but the string must be formatted everytime you need it.

See crate::dtoa!() for a quick 1-line format macro.

assert_eq!(DtoaTmp::new().format(1.0), "1.0");

You could keep a DtoaTmp around to use it as a factory to keep formatting new strings, as it will reuse the inner buffer:

let mut dtoa = DtoaTmp::new();

assert_eq!(dtoa.format(1.0), "1.0");
assert_eq!(dtoa.format(2.0), "2.0");
assert_eq!(dtoa.format(3.0), "3.0");

Size

assert_eq!(std::mem::size_of::<readable::DtoaTmp>(), 25);

Implementations§

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impl DtoaTmp

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pub const fn new() -> Self

Create a new DtoaTmp.

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pub fn format<N: IntoDtoa>(&mut self, num: N) -> &str

Format an IntoDtoa into a &str with an existing DtoaTmp

This function will properly format non-finite floats.

See DtoaTmp::format_finite() if you know your float is finite (not f32::NAN, f32::INFINITY, f32::NEG_INFINITY).

// We can cheaply reuse this.
let mut dtoa = DtoaTmp::new();

assert_eq!(dtoa.format(18.425),  "18.425");
assert_eq!(dtoa.format(19.0918), "19.0918");
assert_eq!(dtoa.format(1.0),     "1.0");

assert_eq!(dtoa.format(f32::NAN),          "NaN");
assert_eq!(dtoa.format(f32::INFINITY),     "inf");
assert_eq!(dtoa.format(f32::NEG_INFINITY), "-inf");

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pub fn format_finite<N: IntoDtoa>(&mut self, num: N) -> &str

Format an IntoDtoa into a &str with an existing DtoaTmp

This function will not properly format non-finite floats.

See DtoaTmp::format() for non-finite float formatting (not f32::NAN, f32::INFINITY, f32::NEG_INFINITY).

// We can cheaply reuse this.
let mut dtoa = DtoaTmp::new();

assert_eq!(dtoa.format_finite(18.425),  "18.425");
assert_eq!(dtoa.format_finite(19.0918), "19.0918");

// This is safe, but the output strings will be incorrect.
assert_eq!(dtoa.format_finite(f64::NAN),          "2.696539702293474e308");
assert_eq!(dtoa.format_finite(f64::INFINITY),     "1.797693134862316e308");
assert_eq!(dtoa.format_finite(f64::NEG_INFINITY), "-1.797693134862316e308");