Delphi Clinic C++Builder Gate Training & Consultancy Delphi Notes Weblog Dr.Bob's Webshop
Dr.Bob's Kylix Kicks
 Borland C++Builder lost+found #1
See Also: C++Builder Papers and Columns

This is the first installment of lost+found. In this series I will discuss small problems, little gems and other stuff that I stumble on to. Have fun.

matherr
Recently somebody complained about the fact that a program that had a custom error handler for mathematical errors did not compile anymore. Upon trying the example program that came with the _matherr and _matherrl documentation I initially got the same results. Consultation of the RTL source and <math.h> soon gave me the insight that since C++ defines an 'exception' class in the standard C++ library that there is a name conflict with the typenames of the arguments passed to _matherr and _matherrl:

  int _matherr(struct exception* e);
  int _matherrl(struct exceptionl* e);
In <math.h> a #define is used to circumvent such conflicts, therefore, when compiling a C++ program that uses this construct to handle math errors, you must write instead of the above:
  int matherr(struct math_exception* e);
  int matherrl(struct math_exceptionl* e);
This solves any name conflicts with types in the Standard C++ Library and the 'regular' C runtime library.


This webpage © 2000-2017 by Bob Swart (aka Dr.Bob - www.drbob42.com). All Rights Reserved.