Performing compile-time assertion checks with static_assert

In C++, it is possible to perform both runtime and compile-time assertion checks to ensure that specific conditions in your code are true. Runtime assertions have the disadvantage that they are verified late when the program is running, and only if the control flow reaches them. There is no alternative when the condition depends on runtime data; however, when that is not the case, compile-time assertion checks are to be preferred. With compile-time assertions, the compiler is able to notify you early in the development stage with an error that a particular condition has not been met. These, however, can only be used when the condition can be evaluated at compile time. In C++11, compile-time assertions are performed with static_assert.

Getting ready

The most common use of static assertion checks is with template metaprogramming, where they can be used for validating that preconditions on template types are met (examples...