Manual

UTF-8 string routines

About UTF-8 string routines
UTF-8 string types
- ALLEGRO_USTR
- ALLEGRO_USTR_INFO
Creating and destroying strings
Predefined strings
- al_ustr_empty_string
Creating strings by referencing other data
Sizes and offsets
Getting code points
Inserting into strings
Appending to strings
Removing parts of strings
Assigning one string to another
Replacing parts of string
- al_ustr_set_chr
- al_ustr_replace_range
Searching
Comparing
UTF-16 conversion
Low-level UTF-8 routines
- al_utf8_width
- al_utf8_encode
Low-level UTF-16 routines
- al_utf16_width
- al_utf16_encode

al_ustr_prev_get

int32_t al_ustr_prev_get(const ALLEGRO_USTR *us, int *pos) Introduced in 5.0.0

Find the beginning of a code point before *pos, then return it. Note this performs a pre-increment.

On success returns the code point value. If pos was out of bounds (e.g. past the end of the string), return -1. On an error, such as an invalid byte sequence, return -2. As with al_ustr_prev, invalid byte sequences may be skipped while advancing.