test_assignment assumes fabs(float)

[hstong@…]

As per [lib.c.math] paragraphs 5 and 6, there are float and long double overloads for fabs():

  float fabs (float);
  long double fabs (long double);

libstdc++ apparently does not have the required overloads and is seems

libs/numeric/ublas/test/test_assignment.cpp

relies on this.

Patch provided.

[hstong@…]

Add cast so fabs() call is proper.

[Steven Watanabe]

It would be better to cast to double instead of float.

[hstong@…]

Yes, this should have been a cast to double.

[j.ungermann@…]

This breaks a couple of tests with non-gcc compilers. So one should call it a bug. A different fix might be calling std::abs instead of std::fabs.