Function sz_string_erase

include/stringzilla/small_string.h:438–472

}

SZ_PUBLIC sz_size_t sz_string_erase(sz_string_t *string, sz_size_t offset, sz_size_t length) {

    sz_assert_(string && "String can't be SZ_NULL.");

    sz_ptr_t string_start;
    sz_size_t string_length;
    sz_size_t string_space;
    sz_bool_t string_is_external;
    sz_string_unpack(string, &string_start, &string_length, &string_space, &string_is_external);

    // Normalize the offset, it can't be larger than the length.
    offset = sz_min_of_two(offset, string_length);

    // We shouldn't normalize the length, to avoid overflowing on `offset + length >= string_length`,
    // if receiving `length == SZ_SIZE_MAX`. After following expression the `length` will contain
    // exactly the delta between original and final length of this `string`.
    length = sz_min_of_two(length, string_length - offset);

    // There are 2 common cases, that wouldn't even require a `memmove`:
    //      1.  Erasing the entire contents of the string.
    //          In that case `length` argument will be equal or greater than `length` member.
    //      2.  Removing the tail of the string with something like `string.pop_back()` in C++.
    //
    // In both of those, regardless of the location of the string - stack or heap,
    // the erasing is as easy as setting the length to the offset.
    // In every other case, we must `memmove` the tail of the string to the left.
    if (offset + length < string_length)
        sz_move(string_start + offset, string_start + offset + length, string_length - offset - length);

    // The `string->external.length = offset` assignment would discard last characters
    // of the on-the-stack string, but inplace subtraction would work.
    string->external.length -= length;
    string_start[string_length - length] = 0;
    return length;
}

SZ_PUBLIC void sz_string_free(sz_string_t *string, sz_memory_allocator_t *allocator) {
    if (!sz_string_is_on_stack(string))