Limit C++ flags to this library itself.

Resolves #159.

Signed-off-by: Tao He <sighingnow@gmail.com>

CMakeLists.txt

@@ -41,19 +41,36 @@ if(MSVC)
     set(CMAKE_GNUtoMS ON)
 endif()
 
-macro(use_cxx11)
+if(NOT (CMAKE_CXX_COMPILER_LAUNCHER MATCHES "ccache") AND NOT (CMAKE_C_COMPILER_LAUNCHER MATCHES "ccache"))
+    find_program(ccache_EXECUTABLE ccache)
+    if(ccache_EXECUTABLE)
+        set(CMAKE_C_COMPILER_LAUNCHER ${ccache_EXECUTABLE})
+        set(CMAKE_CXX_COMPILER_LAUNCHER ${ccache_EXECUTABLE})
+        add_custom_target(ccache-stats
+            COMMAND ${ccache_EXECUTABLE} --show-stats
+        )
+    else()
+        add_custom_target(ccache-stats
+            COMMAND echo "ccache not found."
+        )
+    endif(ccache_EXECUTABLE)
+endif()
+
+macro(use_cxx11 target)
     if(CMAKE_VERSION VERSION_LESS "3.1")
         if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
+            target_compile_options(${target} PRIVATE "-std=gnu++11")
+        else()
+            target_compile_options(${target} PRIVATE "-std=c++11")
         endif()
     else()
-    set(CMAKE_CXX_STANDARD 11)
+        set_target_properties(${target} PROPERTIES
+            CXX_STANDARD 11
+            CXX_STANDARD_REQUIRED ON
+        )
     endif()
 endmacro(use_cxx11)
 
-# ensure C++11
-use_cxx11()
-
 find_package(Boost REQUIRED COMPONENTS system thread random)
 if(APPLE)
     # If we're on OS X check for Homebrew's copy of OpenSSL instead of Apple's

src/CMakeLists.txt

@@ -18,11 +18,13 @@ file(GLOB_RECURSE CPP_CLIENT_CORE_SRC
 )
 
 add_library(etcd-cpp-api-core-objects OBJECT ${CPP_CLIENT_CORE_SRC} ${PROTOBUF_GENERATES})
+use_cxx11(etcd-cpp-api-core-objects)
 add_dependencies(etcd-cpp-api-core-objects protobuf_generates)
 include_generated_protobuf_files(etcd-cpp-api-core-objects)
 
 # add the core library, includes the sycnhronous client only
 add_library(etcd-cpp-api-core $<TARGET_OBJECTS:etcd-cpp-api-core-objects>)
+use_cxx11(etcd-cpp-api-core)
 target_link_libraries(etcd-cpp-api-core PUBLIC
                       ${Boost_LIBRARIES}
                       ${PROTOBUF_LIBRARIES}
@@ -34,6 +36,7 @@ include_generated_protobuf_files(etcd-cpp-api-core)
 # add the client with asynchronus client
 add_library(etcd-cpp-api $<TARGET_OBJECTS:etcd-cpp-api-core-objects>
                          "${CMAKE_CURRENT_SOURCE_DIR}/Client.cpp")
+use_cxx11(etcd-cpp-api)
 target_link_libraries(etcd-cpp-api PUBLIC
                       ${Boost_LIBRARIES}
                       ${CPPREST_LIB}  # n.b.: the asynchronous client requires pplx in cpprestsdk

tst/CMakeLists.txt

@@ -18,6 +18,7 @@ foreach(testfile ${TEST_FILES})
     else()
         add_executable(${test_name} EXCLUDE_FROM_ALL ${CMAKE_CURRENT_SOURCE_DIR}/${testfile})
     endif()
+    use_cxx11(${test_name})
     add_test(NAME ${test_name} COMMAND $<TARGET_FILE:${test_name}>)
 
     target_include_directories(${test_name} PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/../proto/gen)