使用std::bind 出现was not declared in this scope

test.cpp: In function ‘int main()’:
test.cpp:22:8: error: ‘fk’ does not name a type
auto fk = std::bind(func, std::placeholders::_1, 90);
^
test.cpp:23:20: error: ‘fk’ was not declared in this scope
std::cout << fk(1) << endl;

使用std::bind时出现的bug，
原因是：std::bind是C++11的新特性，编译时需要加入stdc++11的库
解决方法：g++ test.cpp -o test -std=c++11

或者直接写cmake

// 针对单文件
cmake_minimum_required(VERSION 2.8)
project(Test)
set(CMAKE_INCLUDE_CURRENT_DIR ON) 
if(CMAKE_COMPILER_IS_GNUCXX)
    set(CMAKE_CXX_FLAGS "-std=c++11 ${CMAKE_CXX_FLAGS} -pthread") # important
endif(CMAKE_COMPILER_IS_GNUCXX)
aux_source_directory(. DIR_SRCS)
add_executable(test test.cpp)