conv

static VALUE
iconv_s_conv(VALUE self, VALUE to, VALUE from, VALUE str)
{
    struct iconv_env_t arg;

    arg.argc = 1;
    arg.argv = &str;
    arg.append = rb_str_append;
    arg.ret = rb_str_new(0, 0);
    arg.cd = iconv_create(to, from, NULL, &arg.toidx);
    return rb_ensure(iconv_s_convert, (VALUE)&arg, iconv_free, ICONV2VALUE(arg.cd));
}