Bound checking and debug macros

To be fast, by default, no check are made on the indices while accessing elements or slicing. However, checks can be activated in two ways:

• Adding the BOUND_CHECK option
• Defining the debug macro TRIQS_ARRAYS_ENFORCE_BOUNDCHECK, which switches the default option to BOUND_CHECK for all arrays, matrices and vectors.

In both cases, if the indices are not within the domain of defintion, an exception triqs::arrays::key_error will be thrown. It’s .what() returns the file and line where the exception occurs, with the stack of all in C++, e.g. :

#define TRIQS_ARRAYS_ENFORCE_BOUNDCHECK
#include <triqs/arrays.hpp>
using triqs::arrays::array;
int main() {
  try {
    array<double, 2> A(2, 2);
    A() = 3;
    std::cout << A(0, 3) << std::endl;
  }
  // catch (triqs::arrays::key_error & e) { std::cout<< e.what()<< std::endl;}
  catch (std::exception &e) {
    std::cout << e.what() << std::endl;
  } // or like this : triqs::arrays::key_error derives from std::exception
}

Note

Bound Checking is not necessarly used for debugging. You may used it for a given array, catching exception. Beware however that bound checking comes with some performance penalty.