devela::_dep::sdl3::sys::stdinc

Function SDL_StepBackUTF8

pub unsafe extern "C" fn SDL_StepBackUTF8(
    start: *const i8,
    pstr: *mut *const i8,
) -> u32 ⓘ
Available on crate feature dep_sdl3 only.
Expand description

Decode a UTF-8 string in reverse, one Unicode codepoint at a time.

This will go to the start of the previous Unicode codepoint in the string, move *pstr to that location and return that codepoint.

If *pstr is already at the start of the string), it will not advance *pstr at all.

Generally this function is called in a loop until it returns zero, adjusting its parameter each iteration.

If an invalid UTF-8 sequence is encountered, this function returns SDL_INVALID_UNICODE_CODEPOINT.

Several things can generate invalid UTF-8 sequences, including overlong encodings, the use of UTF-16 surrogate values, and truncated data. Please refer to RFC3629 for details.

§Parameters

  • start: a pointer to the beginning of the UTF-8 string.
  • pstr: a pointer to a UTF-8 string pointer to be read and adjusted.

§Return value

Returns the previous Unicode codepoint in the string.

§Thread safety

It is safe to call this function from any thread.

§Availability

This function is available since SDL 3.2.0.