This is a collection of example CMake projects demonstrating different ways of building
and using vendored copy of Boost.

project1 and project2 use ExternalProject to build Boost with b2, then "find" it from
the base project. SImilar approaches can be used for other 3rd party libraries
which install their CMake integration files.

project0 uses ExternalProject to build Boost with b2, and performs manual set up for
"imported" Boost target. It's probably the most straightforward solution, however
it doesn't use find_package() and therefore can be considered low-level and potentially
fragile. However, this approach is the most generic: the same way can be used with any
3rd party library, even if it doesn't provide CMake integration files or have
a corresponding Find-module.

project3 uses Orphis/boost-cmake (which internally uses FetchContent and builds source
files of Boost as a part of "main" cmake project. See its CMakeLists.txt for more details.

Building
-------
cd projectN
mkdir build
cd build
cmake ..