gistfile1.h

static VALUE
str_new(VALUE klass, const char *ptr, long len)
{
    VALUE str;

    if (len < 0) {
	rb_raise(rb_eArgError, "negative string size (or size too big)");
    }

    if (ptr != NULL) {
		str = rb_string_new_with_encoded_data(klass, ptr, len, kCFStringEncodingUTF8);
	} 
	else if (len == 0) {
		str = str_alloc(klass);
	}
	else {
		str = rb_bytestring_new();
		rb_bytestring_resize(str, len);
	}
	
	return str;
}

VALUE rb_string_new_with_encoded_data(VALUE klass, const UInt8 *buf, long size, CFStringEncoding enc)
{
	VALUE s = str_alloc(klass);
	CFStringRef to_append = CFStringCreateWithBytes(NULL, buf, (CFIndex)size, enc, false);
	if (to_append != NULL) {
		CFStringAppend((CFMutableStringRef)s, to_append);
		return s;
	}
	// encoding FAIL, let's use a bytestring instead.
	return rb_bytestring_new_with_data(buf, size);
}