Once again, I'd make the point that at least one more level of call context information should be output for the convenience of the user. All I got from DMC++ was:

H:\STLSoft\Releases\1.8.x\STLSoft\include\stlsoft/./unittest/type_traits_uni
ttest_.h(43) : Error: ambiguous match of class template partial specializa
tion 'base_type_traits'
            type_traits_type_test_array_or_pointer_<1>(ai);
                                                         ^
H:\STLSoft\Releases\1.8.x\STLSoft\include\stlsoft/./unittest/type_traits_uni
ttest_.h(325) : Error: undefined identifier 'ai'
            type_traits_type_test_array_or_pointer_<1>(aci);
                                                          ^
H:\STLSoft\Releases\1.8.x\STLSoft\include\stlsoft/./unittest/type_traits_uni
ttest_.h(326) : Error: undefined identifier 'aci'
            type_traits_type_test_array_or_pointer_<1>(avi);
                                                          ^
H:\STLSoft\Releases\1.8.x\STLSoft\include\stlsoft/./unittest/type_traits_uni
ttest_.h(327) : Error: undefined identifier 'avi'
            type_traits_type_test_array_or_pointer_<1>(acvi);
                                                           ^
H:\STLSoft\Releases\1.8.x\STLSoft\include\stlsoft/./unittest/type_traits_uni
ttest_.h(328) : Error: undefined identifier 'acvi'


Which didn't exactly nail it down for me.