when to use std::int32_t and std::int64_t

Description

Looks like there have been some conversations around this and thought we should discuss all the places where we need to be explicit about the bit size of the int and when we shouldn't. I'll start us off with refs to previous conversations and lists of our current int32_t and int64_t usage. It would be great to get some follow-up comments about the reasoning behind this.

It looks like the idea is that we want to use int32_t for x, y, z, and extent until we cast them to doubles or int64_ts when we store them in a mapbox::geometry::point. Looks like we use int64_t for id and property values, referred to as v in the code.

References

• https://github.com/mapbox/vtquery/pull/95#discussion_r198340002
• https://github.com/mapbox/vtquery/pull/88
• https://github.com/mapbox/vtquery/pull/89

int32_t/ uint32_t usage

• create_query_point - https://github.com/mapbox/vtquery/blob/master/src/util.hpp#L54-L57
• convert_vt_to_ll - https://github.com/mapbox/vtquery/blob/master/src/util.hpp#L84-L87
• TileObject - https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L64-L66 & https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L93-L95
• QueryData - https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L102 & https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L128
• Execute - https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L278 & https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L301-L304
• HandleOKCallback - https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L433
• NAN_METHOD(vtquery) - https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L507-L536 & https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L605-L613 & https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L651

int64_t/ uint64_t usage

• mapbox::util::variant - https://github.com/mapbox/vtquery/blob/master/src/util.hpp#L40
• create_query_point - https://github.com/mapbox/vtquery/blob/master/src/util.hpp#L52 & https://github.com/mapbox/vtquery/blob/master/src/util.hpp#L68-L78
• convert_vt_to_ll - https://github.com/mapbox/vtquery/blob/master/src/util.hpp#L89
• ResultObject - https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L44
• property_value_visitor - https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L144-L147
• insert_result - https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L201
• Execute - https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L306 & https://github.com/mapbox/vtquery/blob/master/src/vtquery.cpp#L317

Review the prior discussions in pull requests 95, 88, and 89, then inspect the listed integer usages in src/util.hpp and src/vtquery.cpp. Done means reaching agreement on when each integer width should be used and documenting or applying the resulting decision across the referenced functions.