This CMake module works similarly to CheckTypeSize, with the addition of
the CHECK_TYPE_ALIGN_USE_EXTENSION cache variable. This can be set to
something like __alignof__ on Clang or __alignof on MSVC to skip detection
or to provide an extension that is not known by the module. Check the
CheckTypeAlign.c.in source file for known
compilers and their extensions. If you can help expanding the list, please open
an issue.
The only real difference from CheckTypeSize is due to the way alignof is
specified by the C++ and C standards; it cannot accept an expression as its
argument, only a type-id. The compiler extensions all support the former,
however the main target is the standard way, so the tests do not cover
expressions. In C++ mode, you can still use decltype to convert an expression
to a type.
This module requires CMake >= 3.9.
This module is usable as a proper CMake package:
find_package(CheckTypeAlign REQUIRED)
check_type_align(int ALIGNOF_INT)
Make sure find_package can find it when configuring your project.