环境：
xcode9
mac os 10.13
1、下载boost库并解压
2、cd到解压后的文件包内，执行 sh bootstrap.sh（解压后会得到这个脚本文件）。
3、执行./b2 编译整个库。
4、经过一段时间编译后，得到编译后的头文件和库文件。
5、运行 sudo ./b2 install 命令 将编译后的库安装到系统默认路径/usr/local/include下
6、这时候得到的库文件可能只是X86_64此类模拟器架构运行的库，如果需要真机库需要在第3步之后按照实际情况运行以下脚本。sh myBuildBoost.sh
7、运行后会编译出需要架构的库文件，直接将编译完成之后的库文件复制到系统目录下即可。
8、xcode调试，依次在header Search path 和 library search path后添加头文件和库文件路径/usr/local/include /usr/local/lib
9、在build phases ->link binaru with libray中添加需要的库文件。
10、在实际真机运行中可能会要求关闭bitcode，关闭即可运行。
myBuildBoost.sh
#!/bin/sh
# myBuildBoost.sh
# TestMaster
#
# Created by LuoYao on 2017/10/20.
# Copyright © 2017年 kim. All rights reserved.
# 请自行修改路径，cd到boost解压后的目录下
dir=`dirname $0`
cd "/usr/local/boost_1_57_0"
# 如果库文件已存在，直接退出
if [ -e ./stage/lib/libboost_date_time.a ]; then
echo "libraries exist. no need to build."
exit 0
fi
: ${COMPILER:="clang++"}
: ${IPHONE_SDKVERSION:=`xcodebuild -showsdks | grep iphoneos | egrep "[[:digit:]]+\.[[:digit:]]+" -o | tail -1`}
: ${XCODE_ROOT:=`xcode-select -print-path`}
: ${EXTRA_CPPFLAGS:="-DBOOST_AC_USE_PTHREADS -DBOOST_SP_USE_PTHREADS -stdlib=libc++"}
echo "IPHONE_SDKVERSION: $IPHONE_SDKVERSION"
echo "XCODE_ROOT: $XCODE_ROOT"
echo "COMPILER: $COMPILER"
echo "bootstrap"
# 此脚本如果是被Xcode调用的话，会因为xcode export的某些变量导致失败，所以加了env -i。直接在命令行运行此脚本可以把env -i 去掉
# env -i bash ./bootstrap.sh
echo "write project-config.jam"
# 默认生存的project-config.jam是编译Mac版的，这里直接调换掉
rm project-config.jam
cat >> project-config.jam <<EOF
using darwin : ${IPHONE_SDKVERSION}~iphone
: $XCODE_ROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/$COMPILER -arch armv7 -arch armv7s -arch arm64 $EXTRA_CPPFLAGS
: <striper> <root>$XCODE_ROOT/Platforms/iPhoneOS.platform/Developer
: <architecture>arm <target-os>iphone
;
using darwin : ${IPHONE_SDKVERSION}~iphonesim
: $XCODE_ROOT/Toolchains/XcodeDefault.xctoolchain/usr/bin/$COMPILER -arch i386 -arch x86_64 $EXTRA_CPPFLAGS
: <striper> <root>$XCODE_ROOT/Platforms/iPhoneSimulator.platform/Developer
: <architecture>ia64 <target-os>iphone
;
EOF
# 上面的代码里，两个using darwin分别是编译真机版和模拟器版的设置。每多一种CPU架构就要再加一个-arch xxx。
echo "build boost iphone dev"
./bjam -j16 --with-iostreams --with-regex --with-timer --with-exception --with-chrono --with-serialization --with-signals --with-date_time --with-filesystem --with-system --with-thread --build-dir=iphone-build --stagedir=iphone-build/stage toolset=darwin architecture=arm target-os=iphone macosx-version=iphone-${IPHONE_SDKVERSION} define=_LITTLE_ENDIAN link=static stage
echo "build boost iphone sim"
./bjam -j16 --with-iostreams --with-regex --with-timer --with-exception --with-chrono --with-serialization --with-signals --with-date_time --with-filesystem --with-system --with-thread --build-dir=iphonesim-build --stagedir=iphonesim-build/stage --toolset=darwin-${IPHONE_SDKVERSION}~iphonesim architecture=ia64 target-os=iphone macosx-version=iphonesim-${IPHONE_SDKVERSION} link=static stage cxxflags=-miphoneos-version-min=7.0
echo "lipo"
# 把各架构下的库文件合一，以便在xcode里可以少设置些搜索路径。做得更彻底些是各个分库合成一个大库。不过除非是把静态库加入到代码仓库，否则是浪费时间了。要合成的大库话请参考https://gist.github.com/rsobik/7513324原文。
mkdir -p stage/lib
lipo -create iphone-build/stage/lib/libboost_iostreams.a iphonesim-build/stage/lib/libboost_iostreams.a -output stage/lib/libboost_iostreams.a
lipo -create iphone-build/stage/lib/libboost_regex.a iphonesim-build/stage/lib/libboost_regex.a -output stage/lib/libboost_regex.a
lipo -create iphone-build/stage/lib/libboost_timer.a iphonesim-build/stage/lib/libboost_timer.a -output stage/lib/libboost_timer.a
lipo -create iphone-build/stage/lib/libboost_exception.a iphonesim-build/stage/lib/libboost_exception.a -output stage/lib/libboost_exception.a
lipo -create iphone-build/stage/lib/libboost_chrono.a iphonesim-build/stage/lib/libboost_chrono.a -output stage/lib/libboost_chrono.a
lipo -create iphone-build/stage/lib/libboost_serialization.a iphonesim-build/stage/lib/libboost_serialization.a -output stage/lib/libboost_serialization.a
lipo -create iphone-build/stage/lib/libboost_signals.a iphonesim-build/stage/lib/libboost_signals.a -output stage/lib/libboost_signals.a
lipo -create iphone-build/stage/lib/libboost_atomic.a iphonesim-build/stage/lib/libboost_atomic.a -output stage/lib/libboost_atomic.a
lipo -create iphone-build/stage/lib/libboost_wserialization.a iphonesim-build/stage/lib/libboost_wserialization.a -output stage/lib/libboost_wserialization.a
lipo -create iphone-build/stage/lib/libboost_date_time.a iphonesim-build/stage/lib/libboost_date_time.a -output stage/lib/libboost_date_time.a
lipo -create iphone-build/stage/lib/libboost_filesystem.a iphonesim-build/stage/lib/libboost_filesystem.a -output stage/lib/libboost_filesystem.a
lipo -create iphone-build/stage/lib/libboost_system.a iphonesim-build/stage/lib/libboost_system.a -output stage/lib/libboost_system.a
lipo -create iphone-build/stage/lib/libboost_thread.a iphonesim-build/stage/lib/libboost_thread.a -output stage/lib/libboost_thread.a
# 库文件最终放在./stage/lib/下
echo "Completed successfully"