Allow using system-wide installed args library

Author: TheAssassin

CMakeLists.txt

@@ -91,6 +91,7 @@ find_package(PkgConfig)
 pkg_check_modules(libgcrypt REQUIRED IMPORTED_TARGET libgcrypt)
 
 option(USE_SYSTEM_CPR OFF "Use system-wide installed CPR")
+option(USE_SYSTEM_ARGS OFF "Use system-wide installed args")
 
 # makes linking to static libraries easier
 option(CMAKE_POSITION_INDEPENDENT_CODE ON)
@@ -100,6 +101,13 @@ if(USE_SYSTEM_CPR)
     add_library(cpr ALIAS cpr::cpr)
 endif()
 
+if(USE_SYSTEM_ARGS)
+    find_package(args REQUIRED)
+
+    # need to create an alias target to ease linking
+    add_library(args ALIAS taywee::args)
+endif()
+
 # add libraries shipped along with the project
 add_subdirectory(lib)
 

lib/CMakeLists.txt

@@ -31,10 +31,12 @@ if(NOT USE_SYSTEM_CPR)
     set_property(TARGET cpr PROPERTY POSITION_INDEPENDENT_CODE ON)
 endif()
 
-# it's quite simple dealing with the args library directly from CMake
-add_library(args INTERFACE)
-target_sources(args INTERFACE "${CMAKE_CURRENT_SOURCE_DIR}/args/args.hxx")
-target_include_directories(args INTERFACE args)
+if(NOT USE_SYSTEM_ARGS)
+    # it's quite simple dealing with the args library directly from CMake
+    add_library(args INTERFACE)
+    target_sources(args INTERFACE "${CMAKE_CURRENT_SOURCE_DIR}/args/args.hxx")
+    target_include_directories(args INTERFACE args)
+endif()
 
 # Google Test framework
 if(BUILD_TESTING AND NOT TARGET gtest)