PSA: Some boost libraries didn't compile

[s9w]

#include <boost/asio.hpp>

Failed with: Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately. [...]

#include <boost/json/src.hpp>

complained about a missing link file (LINK : fatal error LNK1104: cannot open file 'libboost_container-vc142-mt-gd-x64-1_76.lib') although according to the manual this should be header-only.

And with beast I have no idea what headers are usually used?

If any of those libs are of interests, I may look into it again.

[vinniefalco]

Boost.Asio and Boost.Beast are very heavy to compile, they are not representative of libraries that are in any way "fast." In order to use these libraries effectively (i.e. for them to have reasonable compilation times) users are required to be very mindful and meticulous about the physical structure of their declarations which use those library components. Type-erasure is must here, as exposing asio.hpp or beast.hpp in commonly included public headers will incur large compilation costs.

The John Lakos book "Large-Scale C++ Software Design" is helpful in this context.

[s9w]

Thanks @vinniefalco for the insights! They seem not a good fit for this overview then, and would probably dwarf the rest either way.

[vinniefalco]

and would probably dwarf the rest either way.

Yeah, you could say that :)

[vinniefalco]

although according to the manual this should be header-only

Yes it should work, but depending on how your build scripts are set up it might not. When including src.hpp (i.e. "header-only") you want Boost's "autolink" feature to be off.

How do your build scripts include Boost.JSON? Are you using CMake? B2?

[s9w]

I go in raw, i.e. call cl.exe directly. No build system

[vinniefalco]

RAW!!! heh... anyway, try defining BOOST_CONTAINER_NO_LIB (this disables auto-linking for Boost.Container).

[s9w]

Hm that works "a bit": Works for a single TU. But when I interpreted the documentation correctly, the idea is to have one TU with

#include <boost/json/src.hpp>

and all others with:

#include <boost/json.hpp>

But with a second TU, the LINK : fatal error LNK1104: cannot open file 'libboost_json-vc142-mt-gd-x64-1_76.lib'is back again

[vinniefalco]

hmm I guess you have to also define BOOST_JSON_NO_LIB (to prevent autolinking to Boost.JSON). I will open an issue so that the usage instructions make this clear.

[s9w]

That works, thanks for your help. I'm going to have to rerun all times because the baseline changed with the single json/src.hpp. So boost.json will be up tomorrow or so.

[vinniefalco]

Cool! Yeah, just remember that we care about the time for including <boost/json.hpp>, not <boost/json/src.hpp>, since the src.hpp definitions are provided by the linked library (or the user's one TU they included it in).

[s9w]

I added boost/json.hpp to the overview so I consider this done. Thanks for the support again.