https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85098
Bug ID: 85098
Summary: undefined reference to std::regex::extended
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
Assignee: unassigned at gcc dot gnu.org
Reporter: john.salmon at deshaw dot com
Target Milestone: ---
When I compile with -std=c++11 or -std=c++14 and with -O0, I get this undefined
reference. With -std=c++17, there's no problem. With -O1 and higher, there's
no problem. Note that with -std=c++14 and 17, 'mu' is just plain-old
std::make_unique. To demonstrate the problem with -std=c++11, I had to define
"my own" make_unique.
drdws0134$ cat foo.cpp
#include <memory>
#include <regex>
#if __cplusplus >= 201402L
#define mu std::make_unique
#else
template <typename T, typename ... Args>
std::unique_ptr<T> mu(Args&& ... args){
return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
}
#endif
auto re = mu<std::regex>("hello", std::regex::extended);
int main(int, char **){
return 0;
}
drdws0134$
drdws0134$ garden with -m gcc/7.3.0-01c7/bin g++ -std=c++11 -O0 foo.cpp
/tmp/ccJeBOid.o: In function `__static_initialization_and_destruction_0(int,
int)':
foo.cpp:(.text+0xd9): undefined reference to `std::__cxx11::basic_regex<char,
std::__cxx11::regex_traits<char> >::extended'
collect2: error: ld returned 1 exit status
drdws0134$ garden with -m gcc/7.3.0-01c7/bin g++ -std=c++14 -O0 foo.cpp
/tmp/cc2NKXJx.o: In function `__static_initialization_and_destruction_0(int,
int)':
foo.cpp:(.text+0xd9): undefined reference to `std::__cxx11::basic_regex<char,
std::__cxx11::regex_traits<char> >::extended'
collect2: error: ld returned 1 exit status
drdws0134$ garden with -m gcc/7.3.0-01c7/bin g++ -std=c++17 -O0 foo.cpp
drdws0134$
