/* Assert a build-time dependency, as an expression.

   Your compile will fail if the condition isn't true, or can't be evaluated
   by the compiler. This can be used in an expression: its value is 0.

   Example:

   #define foo_to_char(foo)  \
       ((char *)(foo)        \
        + Py_BUILD_ASSERT_EXPR(offsetof(struct foo, string) == 0))

   Written by Rusty Russell, public domain, http://ccodearchive.net/ */
#define Py_BUILD_ASSERT_EXPR(cond) \
    (sizeof(char [1 - 2*!(cond)]) - 1)
 
#define Py_BUILD_ASSERT(cond)  do {         \
        (void)Py_BUILD_ASSERT_EXPR(cond);   \
    } while(0)

void foo(int param)
{
    Py_BUILD_ASSERT(param > 0);
}

#define Py_BUILD_ASSERT(cond)  do { \
        Py_DEPRECATED(3.14) \
        int _Py_BUILD_ASSERT_is_deprecated_use_static_assert_instead = 0; \
        _Py_BUILD_ASSERT_is_deprecated_use_static_assert_instead; \
        static_assert(cond, ""); \
    } while(0)

#if defined(__cplusplus)
    template<typename T>
    struct _Py_BUILD_ASSERT_EXPR_prohibit_vla {
        static_assert(sizeof(T) == 1,
            "Py_BUILD_ASSERT_EXPR can only be used with constant "
            "expression of value true");
    };
#  define Py_BUILD_ASSERT_EXPR(cond) \
        (!sizeof(_Py_BUILD_ASSERT_EXPR_prohibit_vla<char[1 - 2 * !(cond)]>))
#elif defined(_MSC_VER)
#  define Py_BUILD_ASSERT_EXPR(cond) \
        (!sizeof( \
            __pragma(warning(push)) \
            __pragma(warning(suppress: 4116)) \
            enum { \
                Py_CONCAT(_Py_BUILD_ASSERT_EXPR_prohibit_vla_,__LINE__) = \
                    sizeof(char[1 - 2 * !(cond)]) \
            } \
            __pragma(warning(pop)) \
        ))
#else
#  define Py_BUILD_ASSERT_EXPR(cond) \
        (!sizeof( \
            enum { \
                Py_CONCAT(_Py_BUILD_ASSERT_EXPR_prohibit_vla_,__LINE__) = \
                    sizeof(char[1 - 2 * !(cond)]) \
            } \
        ))
#endif