That's a C library routine. Isn't it rather in the default namespace (::) instead of "std": ::strtoull? Thanks, Lyle Taylor -----Original Message----- From: Wei Qin [mailto:wqin@xxxxxxxxxxxxxxxx] Sent: Monday, September 22, 2003 7:05 PM To: gcc-help@xxxxxxxxxxx Subject: strtoull undeclared in namespace std Hi, My code does something like #include <cstdlib> ... val = std::strtoull(str, NULL, 0); It worked fine for a while. But recently as I began to use g++3.3.1(on cygwin), it breaks with the error message in the subject. I couldn't find a portable fix for this problem. Please help. thanks in advance, Wei