bool is_something_ok(int param,SomeStruct* p)
{
    bool is_ok = false;

    // check if is_ok

    if(is_ok)
       // set p to some valid value
    else
       // set p to NULL
    return is_ok;
}

this function return true and set p to a valid value if "something is ok" otherwise return false and set p to NULL

Is that a good or bad design? personally, i feel uncomfortable when i use it. If there is no document and comment, i really don know how to use it.

BTW:Is there some authoritative book/article about API design?