How can I resolve the occuring ambiguity when using clog for computing the natural logarithm with complex numbers?

Question

I have a complex double array eigenvalues of which I want to get the natural logarithm of each entry by using clog.

for (int i = 0; i < n; ++i)
{
    qq[i] = clog(eigenvalues[i]);
}

I already dropped the using namespace std; but am still getting error: reference to 'clog' is ambiguous.

How can I make it clear that I want to use the clog from complex.h and not from iostream?

score 3 · Accepted Answer · answered Mar 03 '19 at 20:12

3

I haven't been able to reproduce this with gcc 7.3 without using namespace std but in general all functions from C headers reside in the global namespace. Therefore you should be able to resolve the ambiguity by prefixing clog with :::

for (int i = 0; i < n; ++i)
{
    qq[i] = ::clog(eigenvalues[i]);
}

answered Mar 03 '19 at 20:12

darkwisebear

131
5

1

Agreed, you must have a `using namesapce std` elsewhere - maybe in an included header? – tinkertime Mar 03 '19 at 20:13
This solved it, thanks. Yes, in one header I'm including it was used. – dYTe Mar 03 '19 at 20:18

How can I resolve the occuring ambiguity when using clog for computing the natural logarithm with complex numbers?

1 Answers1