Behavior - all of boost is installed when all I want is Asio

[pfeatherstone]

I ran:

include(cmake/FetchBoostContent.cmake)

FetchBoostContent_Declare(
    boost_asio
    GIT_REPOSITORY https://github.com/boostorg/asio
    GIT_TAG        master
)
FetchBoostContent_MakeAvailable(boost_asio)

And i got

[cmake] -- Fetching (0): boost_asio
[cmake] -- Fetching (1): boost_date_time;boost_chrono;boost_align;boost_coroutine;boost_context;boost_system;boost_pool;boost_io;boost_winapi;boost_variant2;boost_ratio;boost_algorithm;boost_lexical_cast;boost_tokenizer;boost_range;boost_iterator;boost_optional;boost_regex;boost_concept_check;boost_array;boost_integer;boost_container;boost_numeric_conversion;boost_bind;boost_exception;boost_unordered;boost_conversion;boost_throw_exception;boost_predef;boost_describe;boost_mp11;boost_smart_ptr;boost_intrusive;boost_fusion;boost_tuple;boost_static_assert;boost_container_hash;boost_functional;boost_config;boost_mpl;boost_type_traits;boost_core;boost_preprocessor;boost_detail;boost_move;boost_assert;boost_utility;boost_typeof;boost_function;boost_function_types

This downloaded 367 MB of source code. Is this expected?
Am I doing something wrong?
I thought Asio was pretty self-contained.
Thanks

[pfeatherstone]

I think I might just use standalone asio.

[alandefreitas]

Yes. Asio + its dependencies is huge: https://alandefreitas.github.io/boostdep_graph/libs/asio.html

50 transitive dependencies.

A few of these dependencies are completely reimplemented in the standalone version of the library. Most of them are due to C++03 support in Boost.Asio.

So most of these dependencies are going to go away soon because Boost.Asio will also move to C++11 in the next boost releases. When this happens, only things like Boost.Config should remain as Boost.Asio dependencies.

Boost libraries tend to integrate better with Boost.Asio than standalone Asio. So when making the choice between Boost.Asio and standalone Asio I would think more about the probability of needing other Boost libraries in the future than about this number of dependencies.

[pfeatherstone]

Thank you for the quick response. Ok noted. This is still crazy though. Boost is too incestuous

[pfeatherstone]

Like, how is it pulling Boost.geometry ?

Anyway, rant over. I'm still super thankful for this library. Cheers

[alandefreitas]

Well... It's a backwards compatibility trade-off... It's hard to get this right. If Asio were breaking other people's code often, the library wouldn't be very reliable either.

[alandefreitas]

Like, how is it pulling Boost.geometry ?

It's not. It's the other way around. Boost.geometry is the one that depends on Boost.Asio. For boost.geometry, it'd be easier to just fetch all boost libraries. In practice, with the exception of Asio, Boost allows you to do a lot with libraries that are level 1 to 5. For instance, mp11 is great and is level 1 IIRC.