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c++blitz++

How to compare two Blitz++ Arrays?

I am trying to compare two Blitz++ Arrays, but I am getting a compiler error saying that the expression cannot be converted into a boolean.

According to the documentation this operation should be supported.

What am I doing wrong?

Code:

#include <blitz/array.h>

int main() {
  blitz::Array<double, 2> a(1, 1);
  blitz::Array<double, 2> b(1, 1);
  bool c = (a == b);
  return 0;
}

Error:

error: cannot convert ‘blitz::BzBinaryExprResult<blitz::Equal, blitz::Array<double, 2>, blitz::Array<double, 2> >::T_result’ {aka ‘blitz::_bz_ArrayExpr<blitz::_bz_ArrayExprBinaryOp<blitz::_bz_ArrayExpr<blitz::FastArrayIterator<double, 2> >, blitz::_bz_ArrayExpr<blitz::FastArrayIterator<double, 2> >, blitz::Equal<double, double> > >’} to ‘bool’ in initialization
Solution 
  • blitz::Array<bool, 2> result(a == b);

    or

    bool c = blitz::all(blitz::Array<bool, 2>(a == b));

    the conversion from expression to array is explicit.