Default mappers

The following table shows the concrete mapper classes that quince_postgresql will use for each of the polymorphically mapped types, if you don't customize. (The various concrete mapper classes are described here.)

C++ mapped type	quince_postgresql's default concrete mapper class
`bool`	`direct_mapper<bool>`
`int8_t`	`numeric_cast_mapper<int8_t, direct_mapper<int16_t>>`
`int16_t`	`direct_mapper<int16_t>`
`int32_t`	`direct_mapper<int32_t>`
`int64_t`	`direct_mapper<int64_t>`
`float`	`direct_mapper<float>`
`double`	`direct_mapper<double>`
`uint8_t`	`numeric_cast_mapper<uint8_t, direct_mapper<int16_t>>`
`uint16_t`	`numeric_cast_mapper<uint16_t, direct_mapper<int32_t>>`
`uint32_t`	`numeric_cast_mapper<uint32_t, direct_mapper<int64_t>>`
`uint64_t`	`reinterpret_cast_mapper<uint64_t, direct_mapper<int64_t>, uint64_t(0x8000000000000000)>`
`std::string`	`direct_mapper<std::string>`
`std::vector<uint8_t>`	`direct_mapper<std::vector<uint8_t>>`
`quince::serial`	`serial_mapper`
`boost::posix_time::ptime`	`quince_postgresql::ptime_mapper`^[a]
^[a] `quince_postgresql::ptime_mapper` represents a `boost::posix_time::ptime` by delegating to `direct_mapper<timestamp>`, and converting to strings of the form YYYY-mmm-DD HH:MM:SS.fff on the way out, and converting from those strings on the way in.