std：：cout 无法被 gcc 链接器 MacOs 找到

Question

所以我得到了这个链接错误用gcc:

Undefined symbols for architecture x86_64:
"std::__1::locale::use_facet(std::__1::locale::id&) const", referenced from:
std::__1::ctype<char> const& std::__1::use_facet<std::__1::ctype<char> >(std::__1::locale const&) in main-a06879.o
"std::__1::ios_base::getloc() const", referenced from:
std::__1::basic_ios<char, std::__1::char_traits<char> >::widen(char) const in main-a06879.o
"std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::__init(unsigned long, char)", referenced from:
std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::basic_string(unsigned long, char) in main-a06879.o
"std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >::~basic_string()", referenced from:
std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> > std::__1::__pad_and_output<char, std::__1::char_traits<char> >(std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >, char const*, char const*, char const*, std::__1::ios_base&, char) in main-a06879.o
"std::__1::basic_ostream<char, std::__1::char_traits<char> >::sentry::sentry(std::__1::basic_ostream<char, std::__1::char_traits<char> >&)", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in main-a06879.o
"std::__1::basic_ostream<char, std::__1::char_traits<char> >::sentry::~sentry()", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in main-a06879.o
"std::__1::cout", referenced from:
_main in main-a06879.o
"std::__1::ctype<char>::id", referenced from:
std::__1::ctype<char> const& std::__1::use_facet<std::__1::ctype<char> >(std::__1::locale const&) in main-a06879.o
"std::__1::locale::~locale()", referenced from:
std::__1::basic_ios<char, std::__1::char_traits<char> >::widen(char) const in main-a06879.o
"std::__1::ios_base::__set_badbit_and_consider_rethrow()", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in main-a06879.o
"std::__1::ios_base::clear(unsigned int)", referenced from:
std::__1::ios_base::setstate(unsigned int) in main-a06879.o
"std::terminate()", referenced from:
___clang_call_terminate in main-a06879.o
"___cxa_begin_catch", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in main-a06879.o
___clang_call_terminate in main-a06879.o
"___cxa_call_unexpected", referenced from:
std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >::failed() const in main-a06879.o
std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >::ostreambuf_iterator(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in main-a06879.o
"___cxa_end_catch", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in main-a06879.o
"___gxx_personality_v0", referenced from:
std::__1::basic_ostream<char, std::__1::char_traits<char> >& std::__1::__put_character_sequence<char, std::__1::char_traits<char> >(std::__1::basic_ostream<char, std::__1::char_traits<char> >&, char const*, unsigned long) in main-a06879.o
std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> > std::__1::__pad_and_output<char, std::__1::char_traits<char> >(std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >, char const*, char const*, char const*, std::__1::ios_base&, char) in main-a06879.o
std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >::failed() const in main-a06879.o
std::__1::ostreambuf_iterator<char, std::__1::char_traits<char> >::ostreambuf_iterator(std::__1::basic_ostream<char, std::__1::char_traits<char> >&) in main-a06879.o
std::__1::basic_ios<char, std::__1::char_traits<char> >::widen(char) const in main-a06879.o
Dwarf Exception Unwind Info (__eh_frame) in main-a06879.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

它似乎找不到负责所有std命名空间函数的库。如果我的hello world程序std::cout链接器无法找到．我的代码编辑器:Visual Studio code也抱怨同样的错误。

#include <iostream>
int main(){
std::cout << "Hello world!n";
return 0;
}

我已经尝试过了:

1. 重新安装Xcode命令行工具
2. 在回答这个之前问过的问题和我一样的问题，我也不使用通过自制安装的clang，而是使用Xcode命令行工具附带的版本

我不知道怎么回事。也许我曾经在我的shell中盲目地使用了一些来自互联网的命令但也许有办法重置所有这些库搜索路径或其他产生这种行为的方法。

Answer 1

我只是遵循了另一个关于Stack Overflow的讨论的建议我只是使用了& ++&;而不是"gcc"就像我之前编译程序时做的那样