I was just poking around into some new stuff in C++0x, when I hit a stumbling block:
#include <list>
#include <cstdio>
using namespace std;
template <typename T,typename F>
void ForEach (list<T> l, F f) {
for (typename list<T>::iterator it=l.begin();it!=l.end();++it)
f(*it);
}
int main() {
int arr[] = {1,2,3,4,5,6};
list<int> l (arr,arr+6);
ForEach(l,[](int x){printf("%d\n",x);});
}
does not compile. I get a load of undefined symbol errors. Here's make
's output:
i386-apple-darwin9-gcc-4.5.0 -std=c++0x -I/usr/local/include -o func main.cpp
Undefined symbols:
"___cxa_rethrow", referenced from:
std::_List_node<int>* std::list<int, std::allocator<int> >::_M_create_node<int const&>(int const&&&) in ccPxxPwU.o
"operator new(unsigned long)", referenced from:
__gnu_cxx::new_allocator<std::_List_node<int> >::allocate(unsigned long, void const*) in ccPxxPwU.o
"___gxx_personality_v0", referenced from:
___gxx_personality_v0$non_lazy_ptr in ccPxxPwU.o
"___cxa_begin_catch", referenced from:
std::_List_node<int>* std::list<int, std::allocator<int> >::_M_create_node<int const&>(int const&&&) in ccPxxPwU.o
"operator delete(void*)", referenced from:
__gnu_cxx::new_allocator<std::_List_node<int> >::deallocate(std::_List_node<int>*, unsigned long) in ccPxxPwU.o
"___cxa_end_catch", referenced from:
std::_List_node<int>* std::list<int, std::allocator<int> >::_M_create_node<int const&>(int const&&&) in ccPxxPwU.o
"std::__throw_bad_alloc()", referenced from:
__gnu_cxx::new_allocator<std::_List_node<int> >::allocate(unsigned long, void const*) in ccPxxPwU.o
"std::_List_node_base::_M_hook(std::_List_node_base*)", referenced from:
void std::list<int, std::allocator<int> >::_M_insert<int const&>(std::_List_iterator<int>, int const&&&) in ccPxxPwU.o
ld:开发者_如何学Go symbol(s) not found
collect2: ld returned 1 exit status
make: *** [func] Error 1
Why is this not working?
Those are link errors. Are you missing a C++ library? What if you used i386-apple-darwin9-g++-4.5.0
?
P.S. I can't test this, as I have gcc 4.2.1 (i686-apple-darwin10-gcc-4.2.1) on my Mac and get:
cc1plus: error: unrecognized command line option "-std=c++0x"
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