# Distributed under the OSI-approved BSD 3-Clause License. See accompanying # file LICENSE.rst or https://cmake.org/licensing for details. #[=======================================================================[.rst: TestForANSIForScope ------------------- This module checks whether the ``CXX`` compiler restricts the scope of variables declared in a for-init-statement to the loop body. Load this module in a CMake project with: .. code-block:: cmake include(TestForANSIForScope) In early C++ (pre-C++98), variables declared in ``for( ...)`` could remain accessible outside the loop after its body (``for() { }``). This module defines the following cache variable: ``CMAKE_NO_ANSI_FOR_SCOPE`` A cache variable containing the result of the check. It will be set to value ``0`` if the for-init-statement has restricted scope (``C++ 98`` and newer), and to value ``1`` if not (``ANSI C++``). .. note:: As of the ``C++ 98`` standard, variables declared in a for-init-statement are restricted to the loop body, making this behavior obsolete. Examples ^^^^^^^^ Including this module will check the ``for()`` loop scope behavior and define the ``CMAKE_NO_ANSI_FOR_SCOPE`` cache variable: .. code-block:: cmake :caption: ``CMakeLists.txt`` include(TestForANSIForScope) file( CONFIGURE OUTPUT config.h CONTENT "#cmakedefine CMAKE_NO_ANSI_FOR_SCOPE" ) which can be then used in a C++ program: .. code-block:: c++ :caption: ``example.cxx`` #include "config.h" #ifdef CMAKE_NO_ANSI_FOR_SCOPE # define for if(false) {} else for #endif See Also ^^^^^^^^ * The :module:`CMakeBackwardCompatibilityCXX` module. #]=======================================================================] if(NOT DEFINED CMAKE_ANSI_FOR_SCOPE) message(CHECK_START "Check for ANSI scope") try_compile(CMAKE_ANSI_FOR_SCOPE SOURCES ${CMAKE_ROOT}/Modules/TestForAnsiForScope.cxx ) if (CMAKE_ANSI_FOR_SCOPE) message(CHECK_PASS "found") set (CMAKE_NO_ANSI_FOR_SCOPE 0 CACHE INTERNAL "Does the compiler support ansi for scope.") else () message(CHECK_FAIL "not found") set (CMAKE_NO_ANSI_FOR_SCOPE 1 CACHE INTERNAL "Does the compiler support ansi for scope.") endif () endif()