CPM.cmake + Boost (header libs only)

CMakeLists.txt

CPMAddPackage(
  NAME Boost
  VERSION 1.76.0
  URL https://boostorg.jfrog.io/artifactory/main/release/1.76.0/source/boost_1_76_0.tar.gz
  DOWNLOAD_ONLY True 
)
if(Boost_ADDED)
  # Define the header-only Boost target
  add_library(Boost::boost INTERFACE IMPORTED GLOBAL)
  target_include_directories(Boost::boost SYSTEM INTERFACE ${Boost_SOURCE_DIR})

  # Disable autolink
  target_compile_definitions(Boost::boost INTERFACE BOOST_ALL_NO_LIB=1)
endif()

# target_link_libraries(your_project Boost::boost)