Fixed #989.

[redboltz]

Removed boost system and date_time from dependency.

[lproj]

This works now with this CMakeLists.txt (I've installed mqtt_cpp#fix_989):

cmake_minimum_required(VERSION 3.14 FATAL_ERROR)

project(CPMExampleBoost)

# ---- Create binary ----

add_executable(CPMExampleBoost main.cpp)
target_compile_features(CPMExampleBoost PRIVATE cxx_std_17)

# ---- Dependencies ----

file(
  DOWNLOAD
  https://github.com/cpm-cmake/CPM.cmake/releases/download/v0.38.3/CPM.cmake
  ${CMAKE_CURRENT_BINARY_DIR}/cmake/CPM.cmake
  EXPECTED_HASH SHA256=cc155ce02e7945e7b8967ddfaff0b050e958a723ef7aad3766d368940cb15494
)
include(${CMAKE_CURRENT_BINARY_DIR}/cmake/CPM.cmake)

CPMAddPackage(
  NAME Boost
  VERSION 1.81.0
  GITHUB_REPOSITORY "boostorg/boost"
  GIT_TAG "boost-1.81.0"
)

set(MQTT_BUILD_EXAMPLES OFF CACHE BOOL "build mqtt_cpp examples" FORCE)
set(MQTT_BUILD_TESTS OFF CACHE BOOL "build mqtt_cpp tests" FORCE)
cpmaddpackage("gh:redboltz/mqtt_cpp#fix_989")

target_link_libraries(CPMExampleBoost PRIVATE Boost::asio)

[codecov]

Codecov Report

Merging #990 (dc90578) into master (070c25a) will decrease coverage by 5.37%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #990      +/-   ##
==========================================
- Coverage   84.13%   78.77%   -5.37%     
==========================================
  Files          65       65              
  Lines       10749    10402     -347     
==========================================
- Hits         9044     8194     -850     
- Misses       1705     2208     +503     

[lproj]

Sorry to bother you again, but I am getting this error now when trying with master. I think it's a CPM limit:

CMake Error at /home/me/build/_deps/mqtt_cpp-src/include/CMakeLists.txt:62 (ADD_LIBRARY):
Target "check_deps" links to target "Boost::boost" but the target was not
found. Perhaps a find_package() call is missing for an IMPORTED target, or
an ALIAS target is missing?

-- Generating done
CMake Generate step failed. Build files cannot be regenerated correctly.
CMake process exited with exit code 1.

As a work-around I first have to define the Boost::boost target before installing mqtt_cpp:

add_library(Boost::boost INTERFACE IMPORTED)
target_include_directories(Boost::boost INTERFACE "${Boost_SOURCE_DIR}")