cmake/Help/guide/tutorial/Step6/MathFunctions/CMakeLists.txt

add_library(MathFunctions mysqrt.cxx)

# state that anybody linking to us needs to include the current source dir
# to find MathFunctions.h, while we don't.
target_include_directories(MathFunctions
          INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}
          )

# does this system provide the log and exp functions?
include(CheckCXXSourceCompiles)
check_cxx_source_compiles("
  #include <cmath>
  int main() {
    std::log(1.0);
    return 0;
  }
" HAVE_LOG)
check_cxx_source_compiles("
  #include <cmath>
  int main() {
    std::exp(1.0);
    return 0;
  }
" HAVE_EXP)

# add compile definitions
if(HAVE_LOG AND HAVE_EXP)
  target_compile_definitions(MathFunctions
                             PRIVATE "HAVE_LOG" "HAVE_EXP")
endif()

# install rules
install(TARGETS MathFunctions DESTINATION lib)
install(FILES MathFunctions.h DESTINATION include)