How to retain your sanity

2011-06-08

... while writing software.

Over the years I have keep a set of functions that moved from one project to the next. These where small functions that served the sole process of retaining my own sanity. After feeling the need to use these functions in two of my free software projects, I decided to encapsulate them in a small library called sanity.

These functions come in two flavors, trace functions and check functions.

The trace functions are quite simple. The actual function is masqueraded by a macro that hides the gitty details. The macros are TRACE_ERROR, TRACE_WARNING, TRACE_INFO and TRACE_DEBUG and take just a string. The macros amend the severity and the current function. By calling add_trace_target you can add a stream to which the output is directed. The function takes the minimum severity as additional parameter, so it is possible create different logs with different severities.

The check function are a set of extended assert functions based on the concepts of design by contact. As with the trace functions, the check functions are wrapped by macros. The macros are ENSURE, ASSERT, REQUIRE and FAIL. All functions, but FAIL take one condition that must be true to pass the test. If the condition is not true an exception is raised. The FAIL function can be used in cases where the control flow of the program reaches a situation that should not occur, such as the default case of a switch statement.

For convenience CHECK_ARGUMENT exists. This is a check function that can be used as shorthand for argument checks. If the check fails, a std::invalid_argument exception is throw.

Since all functions are macros, they can be removed by conditional compilation, although this is not yet implemented.