Assertion message trick

Here is a simple trick to print a message when an assertion is violated. Assuming you have the following assertion:

assert(foo != nullptr);

You then just append the message you want to print to the check with a logical conjunction like this:

assert(foo != nullptr && "Usually due to not calling bar()");

Now, when this assertion fails the following message is printed:

Assertion `foo != nullptr && "Usually due to not calling bar()"' failed.