gistfile1.m

#define ms_invoke_block_if_not_nil(BLOCK, ...) if ((BLOCK)) {(BLOCK)(__VA_ARGS__);}

// Usage:
void (^block)(id, id, id) = void(^)(id parameter1, id parameter2, id parameter3) {
    // ...
};

ms_invoke_block_if_not_nil(block, parameter1, parameter2, parameter3);

// As opposed to:
if (block) {
    block(parameter1, parameter2, parameter3);
}