Android NDK 'std::string' has not been declared

最近使用NDK, 在C++头文件中加入
#include <string>

ndk-build后报错
x.h: fatal error: string: No such file or directory

试着换成
#include <string.h>
ndk-build后继续报错
x.h: error: 'std::string' has not been declared

真是郁闷, 后来在网上搜索了一大圈, 原来是须要让Android NDK支持STL
Import STL libraries to the Android NDK code
> This is a quick tip for those who are beginning to write native Android code.
> As one may have noticed, it isn’t possible to use containers like, string, vector, list inside the NDK samples.
> These are all part of the STL (Standard Template Library), and are expected to be available when writing C++ code.
> The Application.mk, works similarly as the Android manifest file for your NDK code,
> allowing the programmer to add permissions and define other applications' properties, like such as 'enabling' the STL support.

将Application.mk放在jni目录下(内容以下)
APP_STL := stlport_static