Function SDL_utf8strnlen

pub unsafe extern "C" fn SDL_utf8strnlen(
    str: *const i8,
    bytes: usize,
) -> usize

Available on crate feature dep_sdl3 only.

Count the number of codepoints in a UTF-8 string, up to n bytes.

Counts the codepoints, not bytes, in str, excluding the null terminator.

If you need to count the bytes in a string instead, consider using SDL_strnlen().

The counting stops at bytes bytes (not codepoints!). This seems counterintuitive, but makes it easy to express the total size of the string’s buffer.

Since this handles Unicode, it expects the strings to be well-formed UTF-8 and not a null-terminated string of arbitrary bytes. Bytes that are not valid UTF-8 are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), so a malformed or incomplete UTF-8 sequence might increase the count by several replacement characters.

Parameters

• str: The null-terminated UTF-8 string to read. Must not be NULL.
• bytes: The maximum amount of bytes to count.

Return value

Returns The length (in codepoints, excluding the null terminator) of src but never more than maxlen.

Thread safety

It is safe to call this function from any thread.

Availability

This function is available since SDL 3.2.0.

See also

• SDL_utf8strlen
• SDL_strnlen