C++ compilation error when using c++ 11 on Mac - c++11

Question

I was using C++11 to build my project on Mac.
My make file is like:
# -lpcrecpp
#
CXX=g++
CXXFLAGS = -std=c++11 -stdlib=libstdc++ -Wall -pedantic -I.
INC_DIR = include
SRC_DIR = src
OBJ_DIR = obj
BIN_DIR = bin
$(BIN_DIR)/test: | $(BIN_DIR) $(OBJ_DIR) $(SRC_DIR)/main.cpp $(OBJ_DIR)/recognizer.o $(OBJ_DIR)/util.o
$(CXX) $(CXXFLAGS) $(SRC_DIR)/main.cpp -lpcrecpp -o $(BIN_DIR)/test $(OBJ_DIR)/util.o $(OBJ_DIR)/recognizer.o
$(BIN_DIR):
mkdir -p $(BIN_DIR)
$(OBJ_DIR):
mkdir -p $(OBJ_DIR)
$(OBJ_DIR)/recognizer.o: $(SRC_DIR)/recognizer.cpp $(INC_DIR)/recognizer.h
$(CXX) $(CXXFLAGS) -c $(SRC_DIR)/recognizer.cpp -o $(OBJ_DIR)/recognizer.o
$(OBJ_DIR)/util.o: $(SRC_DIR)/util.cpp $(INC_DIR)/util.h
$(CXX) $(CXXFLAGS) -c $(SRC_DIR)/util.cpp -o $(OBJ_DIR)/util.o
clean:
rm -rf $(OBJ_DIR)
rm -rf $(BIN_DIR)
and I got this weird error:
g++ -std=c++11 -stdlib=libstdc++ -Wall -pedantic -I. src/main.cpp -lpcrecpp -o bin/test obj/util.o obj/recognizer.o
In file included from src/main.cpp:15:
In file included from src/../include/util.h:18:
src/../include/parameters.h:32:10: fatal error: 'unordered_map' file not found
#include <unordered_map>
^
1 error generated.
WHen I using -stdlib=libc++, the error (a linking error) is:
g++ -std=c++11 -stdlib=libc++ -Wall -pedantic -I. src/main.cpp -lpcrecpp -o bin/test obj/util.o obj/recognizer.o
Undefined symbols for architecture x86_64:
"RegularRule::analysis(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)", referenced from:
Recognizer::readRegexRules(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >) in recognizer.o
"RegularRule::setIndex(int)", referenced from:
Recognizer::readRegexRules(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >) in recognizer.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [bin/test] Error 1
My gcc version is:
Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1
Apple LLVM version 7.3.0 (clang-703.0.31)
Target: x86_64-apple-darwin15.6.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
SO I'm confused. Can anybody help?
update
I think the problem lies in the pcre library
I tested a simple code like:
#include <iostream>
#include <pcrecpp.h>
using namespace std;
int main() {
cout << "hello world" << endl;
pcrecpp::RE re("h.*o");
return 0;
}
And the compiling error is:
Undefined symbols for architecture x86_64:
"pcrecpp::RE::Init(std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, pcrecpp::RE_Options const*)", referenced from:
pcrecpp::RE::RE(char const*) in helloworld.cpp.o
"pcrecpp::RE::~RE()", referenced from:
_main in helloworld.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [hello] Error 1
make[1]: *** [CMakeFiles/hello.dir/all] Error 2
make: *** [all] Error 2