C++ Operators

The following gives you the level of all C++ operators. It is often useful to know.

Note: post increment and decrement uses a dummy int parameter: T::operator ++ (int) for t++;.

The min and max operators, which were depracated around version 4.0 of gcc/g++ had the same priority as the relational operators (so priority of 9 in my table above.)

C++ Escape Sequences

The following are the standard and not so standard C/C++ escape characters supported in strings.

In general, for a character c, \c will represent c if not otherwise defined in this table.

A backslah followed by a newline is used to continue a line in preprocessor code.

Use RAII with structures allocated by the C library

Once in a while, we make use of a function found in the C library (and at times even other libraries) which return a pointer to an object that needs to be released one we are done with it.

The easiest way to do that with C++ and especially RAII (in case you may get an exception before you reach the line were you would otherwise free the resource) you can use a shared pointer in this way (example for using getifaddrs() as found in snapcommunicator.cpp at this point):

namespace
{

void ifaddrs_deleter(struct ifaddrs * ptr)
{
    freeifaddrs(ptr);
}

} // no name namespace

...
  {
    struct ifaddrs * if_ptr;
    if(getifaddrs(&if_ptr) == 0)
    {
      std::shared_ptr<struct ifaddrs> safe_if_ptr(if_ptr, ifaddrs_deleter);

      ... // do work here, if exception or return, if_ptr gets freed
    }
    // else -- handle error case
  }
...

You may use a lambda function, just know that there are issue in doing so. I find it easier to have an explicit deleter like here. It is pretty nice and simple to use.