Mismatched _WIN32_WINNT version between boost::log and boost::asio on Windows >= 8 environments.

[Adnn]

I had to hunt down a link error today, and I am taking some time to report it here.

On a Windows 10 environment, I am building a project with two distinct libraries:

• Library A links against boost::log
• Library B links against boost::asio and library A

Library B fails to link, with the following linker error:

B.lib: error LNK2038: mismatch detected for 'boost_log_abi': value 'v2s_mt_nt6' doesn't match v alue 'v2s_mt_nt62' in A.lib

As far as I understand, this is because boost::log determines a "default" Windows version of 0x0602 (here) when compiling on Windows >= 8, whereas boost::asio assumes a default Windows version of 0x0601 (here).

Users can solve this issue by setting an explicit Windows API version, yet it could be preferable if it also linked with default values.