Function lexical_core::write_with_options_unchecked

pub unsafe fn write_with_options_unchecked<'a, N: ToLexicalWithOptions, const FORMAT: u128>(
    n: N,
    bytes: &'a mut [u8],
    options: &N::Options,
) -> &'a mut [u8]

Write number to string with custom options.

Returns a subslice of the input buffer containing the written bytes, starting from the same address in memory as the input slice.

• FORMAT - Packed struct containing the number format.
• value - Number to serialize.
• bytes - Buffer to write number to.
• options - Options to customize number parsing.

Safety

If the buffer is not be large enough to hold the serialized number, it will overflow the buffer unless the safe feature is enabled. Buffer overflows are severe security vulnerabilities, and therefore to ensure the function will not overwrite the buffer, provide a buffer with at least {integer}::FORMATTED_SIZE elements. If you are using custom digit precision control or exponent break points for writing floats, these constants may be insufficient to store the serialized number, and up to 1200 bytes may be required with radix support.

Panics

If the provided FORMAT is not valid, the function may panic. Please ensure is_valid() is called prior to using the format, or checking its validity using a static assertion.

Example

#[cfg(feature = "write-floats")] {
// import `BUFFER_SIZE` to get the maximum bytes written by the number.
use lexical_core::BUFFER_SIZE;

let mut buffer = [0u8; BUFFER_SIZE];
let float = 3.14159265359_f32;

const FORMAT: u128 = lexical_core::format::STANDARD;
let options = lexical_core::WriteFloatOptions::new();
unsafe {
    lexical_core::write_with_options_unchecked::<_, FORMAT>(float, &mut buffer, &options);
}

assert_eq!(&buffer[0..9], b"3.1415927");