QT编译时出现指示以下头文件有错误: #ifdefined(__cplusplus)#if__has_cpp_attribute(clang::fallthrough)#defineQ_FALLTHROUGH() [[clang::fallthrough]]#elif__has_cpp_attribute(gnu::fallthrough)#defineQ_FALLTHROUGH() [[gnu::fallthrough]]#elif__has_cpp_attribute(fallthrough)#defineQ_FALLTHROUGH(...