Default values in extensions::data_types::data_types.h

[marwick4]

Check the default values of different types and the return values of the many "catch" expressions. Many appear to return the wrong value. For example,

template <>
constexpr uint64_t kNullValue<uint64_t> = std::numeric_limits<int64_t>::max();

Should not the return value be std::numeric_limits<uint64_t>::max();

For example,

template<> inline
uint64_t data_types::encode<uint64_t,
std::string,
data_types::DOUBLE>(std::string &str) {
uint64_t encval;
double value;
// auto [ptr, ec] = std::from_chars(str.data(), str.data() + str.size(), value);
try { value = stod(str); }
catch(...) { return kNullValue<uint64_t>; }
memcpy(&encval, &value, sizeof(value));
return encval;
}

Should not the catch expression return kNullValue;