boost python def 函数导出

Introduction

def() is the function which can be used to expose C++ functions and callable objects as Python functions in the current scope.

这个函数可以帮助我们将C++中的函数导出到Python中，供Python使用。说实话，真的很好用。

Functions

def

template <class F>void def(char const* name, F f);template <class Fn, class A1>void def(char const* name, Fn fn, A1 const&);template <class Fn, class A1, class A2>void def(char const* name, Fn fn, A1 const&, A2 const&);template <class Fn, class A1, class A2, class A3>void def(char const* name, Fn fn, A1 const&, A2 const&, A3 const&);

Requires: name is an ntbs which conforms to Python's identifier naming rules.

• If Fn is [derived from] object, it will be added to the current scope as a single overload. To be useful, fn should be callable.
• If a1 is the result of an overload-dispatch-expression, only the second form is allowed and fn must be a pointer to function or pointer to member function whose arity is the same as A1's maximum arity.

  Effects: For each prefix P of Fn's sequence of argument types, beginning with the one whose length is A1's minimum arity, adds a name(...) function overload to the current scope. Each overload generated invokes a1's call-expression with P, using a copy of a1's call policies. If the longest valid prefix of A1 contains N types and a1 holds M keywords, an initial sequence of the keywords are used for all but the first N - M arguments of each overload.
  

• Otherwise, fn must be a non-null function or member function pointer, and a single function overload built around fn is added to the current scope. If any of a1-a3 are supplied, they may be selected in any order from the table below.

Memnonic NameRequirements/Type propertiesEffectsdocstringAny ntbs.Value will be bound to the __doc__ attribute of the resulting method overload.policiesA model of CallPoliciesA copy will be used as the call policies of the resulting method overload.keywordsThe result of a keyword-expression specifying no more arguments than thearity of fn.A copy will be used as the call policies of the resulting method overload.

Example

例子，其实按照下面的例子，很容易就明白了。

主要是

第一个参数，填写你在Python中使用他的名字

第二个参数，写上函数指针

第三个参数，填上参数名，好让boost只要你的函数有几个参数。

第四个参数，是描述，可以忽略

其实还有个很重要的是返回协议（return policy )，详见：http://blog.csdn.net/cedricporter/article/details/6828322

#include <boost/python/def.hpp>#include <boost/python/module.hpp>#include <boost/python/args.hpp>using namespace boost::python;char const* foo(int x, int y) { return "foo"; }BOOST_PYTHON_MODULE(def_test){    def("foo", foo, args("x", "y"), "foo's docstring");}

7 March, 2003

© Copyright Dave Abrahams 2002.