No, the class is a very thin wrapper around mpfi so there's practically no error checking. I really should add some error checks to the functions that create new intervals (i.e. assignment operators from two "components"): I'll do that shortly.
Here's the patch for better error checks going in Trunk, hopefully that should stop most invalid intervals from ever occurring in the first place: Index: mpfi.hpp =================================================================== --- mpfi.hpp (revision 86537) +++ mpfi.hpp (working copy) @@ -179,6 +179,8 @@ } mpfi_float_imp& operator = (const char* s) { + using default_ops::eval_fpclassify; + if(m_data[0].left._mpfr_d == 0) mpfi_init2(m_data, multiprecision::detail::digits10_2_2(digits10 ? digits10 : get_default_precision())); @@ -203,7 +205,22 @@ part.erase(); b = part.c_str(); - mpfi_interv_fr(m_data, a.data(), b.data()); + if(eval_fpclassify(a) == FP_NAN) + { + mpfi_set_fr(this->data(), a.data()); + } + else if(eval_fpclassify(b) == FP_NAN) + { + mpfi_set_fr(this->data(), b.data()); + } + else + { + if(a.compare(b) > 0) + { + BOOST_THROW_EXCEPTION(std::runtime_error("Attempt to create interval with invalid range (start is greater than end).")); + } + mpfi_interv_fr(m_data, a.data(), b.data()); + } } else if(mpfi_set_str(m_data, s, 10) != 0) { @@ -745,7 +762,23 @@ template <unsigned D1, unsigned D2, mpfr_allocation_type AllocationType> inline void assign_components(mpfi_float_backend<D1>& result, const mpfr_float_backend<D2, AllocationType>& a, const mpfr_float_backend<D2, AllocationType>& b) { - mpfi_interv_fr(result.data(), a.data(), b.data()); + using default_ops::eval_fpclassify; + if(eval_fpclassify(a) == FP_NAN) + { + mpfi_set_fr(result.data(), a.data()); + } + else if(eval_fpclassify(b) == FP_NAN) + { + mpfi_set_fr(result.data(), b.data()); + } + else + { + if(a.compare(b) > 0) + { + BOOST_THROW_EXCEPTION(std::runtime_error("Attempt to create interval with invalid range (start is greater than end).")); + } + mpfi_interv_fr(result.data(), a.data(), b.data()); + } } template <unsigned Digits10, class V> John.