C++ TypeVector::empty方法代码示例

void
herschel::xml::displayTypeVector(Port<Octet>& port, zstring tagName, const TypeVector& types)
{
  if (!types.empty()) {
    displayOpenTag(port, tagName);
    for (size_t i = 0; i < types.size(); i++)
      herschel::display(port, types[i].toString());
    displayCloseTag(port, tagName);
  }
}

// The scalar cases in llsd_matches() use this helper. In most cases, we can
// accept not only the exact type specified in the prototype, but also other
// types convertible to the expected type. That implies looping over an array
// of such types. If the actual type doesn't match any of them, we want to
// provide a list of acceptable conversions as well as the exact type, e.g.:
// "Integer (or Boolean, Real, String) required instead of UUID". Both the
// implementation and the calling logic are simplified by separating out the
// expected type from the convertible types.
static std::string match_types(LLSD::Type expect, // prototype.type()
                               const TypeVector& accept, // types convertible to that type
                               LLSD::Type actual,        // type we're checking
                               const std::string& pfx)   // as for llsd_matches
{
    // Trivial case: if the actual type is exactly what we expect, we're good.
    if (actual == expect)
        return "";

    // For the rest of the logic, build up a suitable error string as we go so
    // we only have to make a single pass over the list of acceptable types.
    // If we detect success along the way, we'll simply discard the partial
    // error string.
    std::ostringstream out;
    out << colon(pfx) << sTypes.lookup(expect);

    // If there are any convertible types, append that list.
    if (! accept.empty())
    {
        out << " (";
        const char* sep = "or ";
        for (TypeVector::const_iterator ai(accept.begin()), aend(accept.end());
             ai != aend; ++ai, sep = ", ")
        {
            // Don't forget to return success if we match any of those types...
            if (actual == *ai)
                return "";
            out << sep << sTypes.lookup(*ai);
        }
        out << ')';
    }
    // If we got this far, it's because 'actual' was not one of the acceptable
    // types, so we must return an error. 'out' already contains colon(pfx)
    // and the formatted list of acceptable types, so just append the mismatch
    // phrase and the actual type.
    out << op << sTypes.lookup(actual);
    return out.str();
}