trace - portable exception backtracing in C++17

This library uses std::nested_exception and std::throw_with_nested and can be applied in order to not lose information while propagating an original std::exception upwards through a chain of function calls and create a backtrace without any overhead (compare e.g. logging of debug messages). This avoids much of the need for any debugging and provides a way of ensuring that a library does not crash ungracefully.

Usage

#include <trace/trace.hpp>

The library revolves around three macros

• trace::initiate: can be placed anywhere. Takes a std::string message and initiates
  a trace with information about the corresponding function and source file. This is done
  by throwing an exception.
• trace::propagate: should be placed in a catch-block. Takes a std::string message,
  attaches it to the trace and propagates the trace up the function call stack by
  rethrowing a nested exception
• trace::handle: should be placed in a catch-block. Takes a std::exception & and
  unwraps it to creates a backtrace

and the function trace::latest(), which returns the most recent backtrace, created by the call to handle.