Add Intel to cmake file. Supress Intel inline/noinline warning

CMakeLists.txt

@@ -38,7 +38,7 @@ endif()
 string(REPLACE "+" "" PYTHONLIBS_VERSION_STRING "+${PYTHONLIBS_VERSION_STRING}")
 find_package(PythonInterp ${PYTHONLIBS_VERSION_STRING} EXACT REQUIRED)
 
-if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU")
+if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU" OR CMAKE_CXX_COMPILER_ID MATCHES "Intel")
   CHECK_CXX_COMPILER_FLAG("-std=c++14" HAS_CPP14_FLAG)
   CHECK_CXX_COMPILER_FLAG("-std=c++11" HAS_CPP11_FLAG)
 
@@ -57,10 +57,17 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU"
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fvisibility=hidden")
 
     # Check for Link Time Optimization support
+    # (GCC/Clang)
     CHECK_CXX_COMPILER_FLAG("-flto" HAS_LTO_FLAG)
     if (HAS_LTO_FLAG)
       set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -flto")
     endif()
+
+    # Intel equivalent to LTO is called IPO
+    CHECK_CXX_COMPILER_FLAG("-ipo" HAS_IPO_FLAG)
+    if (HAS_IPO_FLAG)
+      set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -ipo")
+    endif()
   endif()
 endif()
 

include/pybind11/pybind11.h

@@ -17,6 +17,8 @@
 #  pragma warning(disable: 4996) // warning C4996: The POSIX name for this item is deprecated. Instead, use the ISO C and C++ conformant name
 #  pragma warning(disable: 4100) // warning C4100: Unreferenced formal parameter
 #  pragma warning(disable: 4512) // warning C4512: Assignment operator was implicitly defined as deleted
+#elif defined(__ICC) || defined(__INTEL_COMPILER)
+#  pragma warning(disable:2196)  // warning #2196: routine is both "inline" and "noinline"
 #elif defined(__GNUG__) and !defined(__clang__)
 #  pragma GCC diagnostic push
 #  pragma GCC diagnostic ignored "-Wunused-but-set-parameter"