Specify CXX language explicitly in CMake

Marking project as CXX will disable detecting C compiler and other checks.
Removed 'INCLUDES DESTINATION' as it made the include path appear doubled.

CMakeLists.txt

@@ -4,7 +4,7 @@
 #
 
 cmake_minimum_required(VERSION 3.1)
-project(spdlog VERSION 0.16.3)
+project(spdlog VERSION 0.16.3 LANGUAGES CXX)
 include(CTest)
 include(CMakeDependentOption)
 include(GNUInstallDirs)
@@ -73,7 +73,6 @@ configure_file("cmake/spdlog.pc.in" "${pkg_config}" @ONLY)
 install(
     TARGETS spdlog
     EXPORT "${targets_export_name}"
-    INCLUDES DESTINATION "${include_install_dir}"
 )
 
 # install headers

example/CMakeLists.txt

-# *************************************************************************/
-# * Copyright (c) 2015 Ruslan Baratov.                                    */
-# *                                                                       */
-# * Permission is hereby granted, free of charge, to any person obtaining */
-# * a copy of this software and associated documentation files (the       */
-# * "Software"), to deal in the Software without restriction, including   */
-# * without limitation the rights to use, copy, modify, merge, publish,   */
-# * distribute, sublicense, and/or sell copies of the Software, and to    */
-# * permit persons to whom the Software is furnished to do so, subject to */
-# * the following conditions:                                             */
-# *                                                                       */
-# * The above copyright notice and this permission notice shall be        */
-# * included in all copies or substantial portions of the Software.       */
-# *                                                                       */
-# * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
-# * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
-# * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
-# * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
-# * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
-# * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
-# * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
-# *************************************************************************/
-
-cmake_minimum_required(VERSION 3.0)
-project(SpdlogExamples)
-
-if(TARGET spdlog)
-  # Part of the main project
-  add_library(spdlog::spdlog ALIAS spdlog)
-else()
-  # Stand-alone build
-  find_package(spdlog CONFIG REQUIRED)
-endif()
-
-find_package(Threads)
-
-add_executable(example example.cpp)
-target_link_libraries(example spdlog::spdlog ${CMAKE_THREAD_LIBS_INIT})
-
-add_executable(benchmark bench.cpp)
-target_link_libraries(benchmark spdlog::spdlog ${CMAKE_THREAD_LIBS_INIT})
-
-add_executable(multisink multisink.cpp)
-target_link_libraries(multisink spdlog::spdlog ${CMAKE_THREAD_LIBS_INIT})
-
-enable_testing()
-file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/logs")
-add_test(NAME RunExample COMMAND example)
-add_test(NAME RunBenchmark COMMAND benchmark)
+# *************************************************************************/
+# * Copyright (c) 2015 Ruslan Baratov.                                    */
+# *                                                                       */
+# * Permission is hereby granted, free of charge, to any person obtaining */
+# * a copy of this software and associated documentation files (the       */
+# * "Software"), to deal in the Software without restriction, including   */
+# * without limitation the rights to use, copy, modify, merge, publish,   */
+# * distribute, sublicense, and/or sell copies of the Software, and to    */
+# * permit persons to whom the Software is furnished to do so, subject to */
+# * the following conditions:                                             */
+# *                                                                       */
+# * The above copyright notice and this permission notice shall be        */
+# * included in all copies or substantial portions of the Software.       */
+# *                                                                       */
+# * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+# * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+# * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+# * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+# * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+# * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+# * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+# *************************************************************************/
+
+cmake_minimum_required(VERSION 3.0)
+project(SpdlogExamples CXX)
+
+if(TARGET spdlog)
+  # Part of the main project
+  add_library(spdlog::spdlog ALIAS spdlog)
+else()
+  # Stand-alone build
+  find_package(spdlog CONFIG REQUIRED)
+endif()
+
+find_package(Threads)
+
+add_executable(example example.cpp)
+target_link_libraries(example spdlog::spdlog ${CMAKE_THREAD_LIBS_INIT})
+
+add_executable(benchmark bench.cpp)
+target_link_libraries(benchmark spdlog::spdlog ${CMAKE_THREAD_LIBS_INIT})
+
+add_executable(multisink multisink.cpp)
+target_link_libraries(multisink spdlog::spdlog ${CMAKE_THREAD_LIBS_INIT})
+
+enable_testing()
+file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/logs")
+add_test(NAME RunExample COMMAND example)
+add_test(NAME RunBenchmark COMMAND benchmark)

tests/CMakeLists.txt

-project(spdlog-utests)
-
-enable_testing()
-find_package(Threads REQUIRED)
-
-set(SPDLOG_UTESTS_SOURCES
-    errors.cpp
-    file_helper.cpp
-    file_log.cpp
-    format.cpp
-    includes.h
-    registry.cpp
-    test_macros.cpp
-    utils.cpp
-    utils.h
-    main.cpp)
-
-add_executable(${PROJECT_NAME} ${SPDLOG_UTESTS_SOURCES})
-target_link_libraries(${PROJECT_NAME} PRIVATE Threads::Threads)
-target_link_libraries(${PROJECT_NAME} PRIVATE spdlog)
-
-add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME})
-file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/logs")
+project(spdlog-utests CXX)
+
+enable_testing()
+find_package(Threads REQUIRED)
+
+set(SPDLOG_UTESTS_SOURCES
+    errors.cpp
+    file_helper.cpp
+    file_log.cpp
+    format.cpp
+    includes.h
+    registry.cpp
+    test_macros.cpp
+    utils.cpp
+    utils.h
+    main.cpp)
+
+add_executable(${PROJECT_NAME} ${SPDLOG_UTESTS_SOURCES})
+target_link_libraries(${PROJECT_NAME} PRIVATE Threads::Threads)
+target_link_libraries(${PROJECT_NAME} PRIVATE spdlog)
+
+add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME})
+file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/logs")