Utility functions and classes for C++, with emphasis on debug utilities.

Three header files are provided:

• simple_debug.hpp: simple version, with easy-to-copy echo and trace macros. Mainly used when you don't want an extra header file in your project for some reason and/or only need very basic functionality.
• debug.hpp: complete version. Simply #include the file and it's ready to use. Complete usage instructions below.
• xtrace.hpp: optional add-on to the complete version. Usage instructions below.

• ECHO: any number of arguments. Prints them all with a line break after each of them.
• ECHOI: indented echo. Receives a number specifying the indentation (the number of tabs) and one or more extra arguments that are printed with the specified indentation.
• TRACE: two possible usages:
  1. TRACE(expression): prints the expression itself and its value, followed by a line break. For example:

  char k = 'A';
  TRACE(k); // prints "k = A"

  2. TRACE(expression, custom_formatter): similar to TRACE(expression), but prints the result of custom_formatter(expression) instead of the value of the expression itself. Anything with a valid operator()(expression) is allowed.
• TRACE_L: two possible usages:
  1. TRACE_L(name, expression): equivalent to TRACE(expression), but displays the value of name as if it was the name of expression.
  2. TRACE_L(name, expression, custom_formatter): same as above, but using a custom formatter.
• BLANK: alias to ECHO(). Prints a line break.
• DEBUG: write this before a line of code to represent a "checkpoint". If the program breaks prematurely (e.g if a segfault occurs), the following informations are printed regarding the last successful usage of DEBUG (see tests/debug_macro_test.cpp for an example):
  1. the line number
  2. the file name
  3. the function name
  4. a string describing the problem.
• DEBUG_REDIRECT: two possible usages:
  1. DEBUG_REDIRECT(stream): redirects all the following debug output to a given output stream, which must be compatible with decltype(std::cout).
  2. DEBUG_REDIRECT(function): every debug message will be forwarded to a given function, which must be compatible with std::function<void(const std::string&)>.
• DEBUG_EXEC: executes an arbitrary code. Useful to execute some code only if the debug mode is active.
• XTRACE: found only in xtrace.hpp. Use it like XTRACE(expression). Works like TRACE(expression), but it can pretty-print several other types like std::vector, std::tuple, etc.

• The following macros can either be set directly in debug.hpp or overriden during compilation:
  • ALLOW_DEBUG_USAGE: if set to 0, every macro usage will do nothing but declare a unused variable inside a new block (to trigger "unused variable" warnings during compilation to make it easy to find all macro usages).
  • DEBUG_ENABLED: if set to 0, every macro usage will do nothing at all.