language: C++ 4.7.2 (gcc-4.7.2)
date: 303 days 22 hours ago
link:
visibility: public 
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#define CAT(a, ...) PRIMITIVE_CAT(a, __VA_ARGS__)
#define PRIMITIVE_CAT(a, ...) a ## __VA_ARGS__
 
#define IIF(c) PRIMITIVE_CAT(IIF_, c)
#define IIF_0(t, ...) __VA_ARGS__
#define IIF_1(t, ...) t
 
#define PROBE(x) x, 1 
 
#define CHECK(...) CHECK_N(__VA_ARGS__, 0)
#define CHECK_N(x, n, ...) n
 
#define ENABLE_USER_gwiazdorrr () // gwiazdorrr is now enabled
#define ENABLE_USER_foo ()        // foo is also enabled
// #define ENABLE_USER_bar ()     // bar is NOT enabled
 
#define USER_ENABLED_PROBE(user)            USER_ENABLED_PROBE_PROXY( ENABLE_USER_##user ) // concatenate prefix with user name
#define USER_ENABLED_PROBE_PROXY(...)       USER_ENABLED_PROBE_PRIMIVIE(__VA_ARGS__)       // expand arguments
#define USER_ENABLED_PROBE_PRIMIVIE(x)      USER_ENABLED_PROBE_COMBINE_ x                  // merge
#define USER_ENABLED_PROBE_COMBINE_(...)    PROBE(~)                                       // if merge successful, expand to probe
 
#define IS_USER_ENABLED(user) CHECK(USER_ENABLED_PROBE(user))
 
 
#define TURN_OPTIMISATION_OFF(user) IIF( IS_USER_ENABLED(user) ) \
    (\
        _Pragma ("GCC optimize \"0\""),\
        /* nothing */ \
    )
 
TURN_OPTIMISATION_OFF(gwiazdorrr) // expands into __pragma optimize("", off)
TURN_OPTIMISATION_OFF(foo)        // expands into __pragma optimize("", off)
TURN_OPTIMISATION_OFF(bar)        // nothing emitted
 
int main()
{
        return 0;
}