Koh-ichiro YOSHIURA <kyoshi@xxxxxxxxxxxxxxxxxxxx> writes: > I am a biology researcher working in University. > I am compiling one calculation program. I had a trouble for compiling on > MacOSX (10.3.9) with gcc 3.3. > > Error massage is following. > "BFunction.cc:615: error: `signbit' undeclared (first use this function)" > > How can I overcome this? I cannot compile because gcc 3.3 is not included > signbit function? This is a question about the C++ language. It is not a question about gcc. So this is the wrong mailing list. First, gcc is a compiler, not a library. The signbit function is provided by your system library. Second, before you can call signbit it must be declared. On GNU/Linux systems, it is declared in math.h, so you must #include <cmath> before calling signbit. (I don't have access to a MacOS X system myself.) Ian
