boost/python
2
0
Fork 0
mirror of https://github.com/boostorg/python.git synced 2026-01-24 18:12:43 +00:00
Code Issues Projects Releases Wiki Activity

Added return_by_value, enhanced data member support to handle constant members

Browse Source 
[SVN r15935]
This commit is contained in:
Dave Abrahams
2002-10-15 15:46:34 +00:00
parent 2c7829f50e
commit c389e057b4
7 changed files with 241 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
doc/v2/reference.html
View File

@@ -13,7 +13,7 @@
p.c3 {font-style: italic}
h2.c2 {text-align: center}
h1.c1 {text-align: center}
</style>
</style>
</head>
<body>
@@ -352,8 +352,8 @@
<dd>
<dl class="index">
<dt><a href="object.html#object-spec">object</a></dt>
</dl>
</dd>
</dl>
</dd>
</dl>
</dd>
@@ -716,6 +716,21 @@
</dd>
</dl>
</dd>
<dt><a href="return_by_value.html">return_by_value.hpp</a></dt>
<dd>
<dl class="index">
<dt><a href="return_by_value.html#classes">Classes</a></dt>
<dd>
<dl class="index">
<dt><a href=
"return_by_value.html#return_by_value-spec">return_by_value</a></dt>
</dl>
</dd>
</dl>
</dd>
</dl>
</dd>
</dl>
@@ -898,7 +913,8 @@
<p>Revised
<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->
08 October, 2002 <!--webbot bot="Timestamp" endspan i-checksum="39359" -->
15 October, 2002
<!--webbot bot="Timestamp" endspan i-checksum="39359" -->
</p>
<p class="c3">&copy; Copyright <a href=

147
doc/v2/return_by_value.html Normal file
View File

@@ -0,0 +1,147 @@
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta name="generator" content=
"HTML Tidy for Windows (vers 1st August 2002), see www.w3.org">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<link rel="stylesheet" type="text/css" href="../boost.css">
<title>Boost.Python - &lt;boost/python/return_by_value.hpp&gt;</title>
</head>
<body>
<table border="0" cellpadding="7" cellspacing="0" width="100%" summary=
"header">
<tr>
<td valign="top" width="300">
<h3><a href="../../../../index.htm"><img height="86" width="277"
alt="C++ Boost" src="../../../../c++boost.gif" border="0"></a></h3>
</td>
<td valign="top">
<h1 align="center">Boost.Python</h1>
<h2 align="center">Header
&lt;boost/python/return_by_value.hpp&gt;</h2>
</td>
</tr>
</table>
<hr>
<h2>Contents</h2>
<dl class="page-index">
<dt><a href="#classes">Classes</a></dt>
<dd>
<dl class="page-index">
<dt><a href="#return_by_value-spec">Class
<code>return_by_value</code></a></dt>
<dd>
<dl class="page-index">
<dt><a href="#return_by_value-spec-synopsis">Class
<code>return_by_value</code> synopsis</a></dt>
<dt><a href="#return_by_value-spec-metafunctions">Class
<code>return_by_value</code> metafunctions</a></dt>
</dl>
</dd>
</dl>
</dd>
<dt><a href="#examples">Example</a></dt>
</dl>
<hr>
<h2><a name="classes"></a>Classes</h2>
<h3><a name="return_by_value-spec"></a>Class
<code>return_by_value</code></h3>
<p><code>return_by_value</code> is a model of <a href=
"ResultConverter.html#ResultConverterGenerator-concept">ResultConverterGenerator</a>
which can be used to wrap C++ functions returning any reference or value
type such that the return value is copied into a new Python object.</p>
<h4><a name="return_by_value-spec-synopsis"></a>Class
<code>return_by_value</code> synopsis</h4>
<pre>
namespace boost { namespace python
{
struct return_by_value
{
template &lt;class T&gt; struct apply;
};
}}
</pre>
<h4><a name="return_by_value-spec-metafunctions"></a>Class
<code>return_by_value</code> metafunctions</h4>
<pre>
template &lt;class T&gt; struct apply
</pre>
<dl class="metafunction-semantics">
<dt><b>Returns:</b> <code>typedef <a href=
"to_python_value.html#to_python_value-spec">to_python_value</a>&lt;T&gt;
type;</code></dt>
</dl>
<h2><a name="examples"></a>Example</h2>
<h3>C++ Module Definition</h3>
<pre>
#include &lt;boost/python/module.hpp&gt;
#include &lt;boost/python/class.hpp&gt;
#include &lt;boost/python/return_by_value.hpp&gt;
#include &lt;boost/python/return_value_policy.hpp&gt;
// classes to wrap
struct Bar { };
Bar global_bar;
// functions to wrap:
Bar b1();
Bar&amp; b2();
Bar const&amp; b3();
// Wrapper code
using namespace boost::python;
template &lt;class R&gt;
void def_void_function(char const* name, R (*f)())
{
def(name, f, return_value_policy&lt;return_by_value&gt;());
}
BOOST_PYTHON_MODULE(my_module)
{
class_&lt;Bar&gt;("Bar");
def_void_function("b1", b1);
def_void_function("b2", b2);
def_void_function("b3", b3);
}
</pre>
<h3>Python Code</h3>
<pre>
&gt;&gt;&gt; from my_module import *
&gt;&gt;&gt; b = b1() # each of these calls
&gt;&gt;&gt; b = b2() # creates a brand
&gt;&gt;&gt; b = b3() # new Bar object
</pre>
<p>Revised
<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->
15 October, 2002
<!--webbot bot="Timestamp" endspan i-checksum="39359" -->
</p>
<p><i>&copy; Copyright <a href=
"../../../../people/dave_abrahams.htm">Dave Abrahams</a> 2002. All Rights
Reserved.</i></p>
</body>
</html>

4
include/boost/python/data_members.hpp
View File

@@ -11,7 +11,7 @@
# include <boost/type_traits/transform_traits.hpp>
# include <boost/type_traits/cv_traits.hpp>
# include <boost/python/return_value_policy.hpp>
# include <boost/python/copy_non_const_reference.hpp>
# include <boost/python/return_by_value.hpp>
# include <boost/python/object/function_object.hpp>
# include <boost/python/arg_from_python.hpp>
# include <boost/bind.hpp>
@@ -65,7 +65,7 @@ namespace detail
template <class C, class D>
object make_getter(D C::*pm)
{
typedef return_value_policy<copy_non_const_reference> default_policy;
typedef return_value_policy<return_by_value> default_policy;
return objects::function_object(
::boost::bind(

15
include/boost/python/object/iterator.hpp
View File

@@ -10,7 +10,7 @@
# include <boost/python/class.hpp>
# include <boost/python/object/class_detail.hpp>
# include <boost/python/return_value_policy.hpp>
# include <boost/python/copy_const_reference.hpp>
# include <boost/python/return_by_value.hpp>
# include <boost/python/object/function_object.hpp>
# include <boost/python/handle.hpp>
# include <boost/type.hpp>
@@ -29,18 +29,7 @@ namespace boost { namespace python { namespace objects {
// iterators are copied, so we just replace the result_converter from
// the default_iterator_call_policies with a permissive one which
// always copies the result.
struct default_iterator_call_policies
: default_call_policies
{
struct result_converter
{
template <class R>
struct apply
{
typedef to_python_value<R> type;
};
};
};
typedef return_value_policy<return_by_value> default_iterator_call_policies;
// Instantiations of these are wrapped to produce Python iterators.
template <class NextPolicies, class Iterator>

30
include/boost/python/return_by_value.hpp Normal file
View File

@@ -0,0 +1,30 @@
// Copyright David Abrahams 2002. Permission to copy, use,
// modify, sell and distribute this software is granted provided this
// copyright notice appears in all copies. This software is provided
// "as is" without express or implied warranty, and with no claim as
// to its suitability for any purpose.
#ifndef BY_VALUE_DWA20021015_HPP
# define BY_VALUE_DWA20021015_HPP
# include <boost/python/to_python_value.hpp>
# include <boost/type_traits/add_reference.hpp>
# include <boost/type_traits/add_const.hpp>
namespace boost { namespace python {
struct return_by_value
{
template <class R>
struct apply
{
typedef to_python_value<
typename add_reference<
typename add_const<R>::type
>::type
> type;
};
};
}} // namespace boost::python
#endif // BY_VALUE_DWA20021015_HPP

25
test/data_members.cpp
View File

@@ -5,6 +5,8 @@
// to its suitability for any purpose.
#include <boost/python/class.hpp>
#include <boost/python/module.hpp>
#include <boost/python/return_value_policy.hpp>
#include <boost/python/return_by_value.hpp>
#include "test_class.hpp"
#if defined(_AIX) && defined(__EDG_VERSION__) && __EDG_VERSION__ < 245
@@ -20,6 +22,16 @@ typedef test_class<1> Y;
double get_fair_value(X const& x) { return x.value(); }
struct Var
{
Var(std::string name_) : name(name_), value(), name2(name.c_str()) {}
std::string const name;
std::string get_name1() const { return name; }
std::string const& get_name2() const { return name; }
float value;
char const* name2;
};
BOOST_PYTHON_MODULE(data_members_ext)
{
class_<X>("X", init<int>())
@@ -34,6 +46,19 @@ BOOST_PYTHON_MODULE(data_members_ext)
.def("set", &Y::set)
.def_readwrite("x", &Y::x)
;
class_<Var>("Var", init<std::string>())
.def_readonly("name", &Var::name)
.def_readonly("name2", &Var::name2)
.def_readwrite("value", &Var::value)
// Test return_by_value for plain values and for
// pointers... return_by_value was implemented as a
// side-effect of implementing data member support, so it made
// sense to add the test here.
.def("get_name1", &Var::get_name1, return_value_policy<return_by_value>())
.def("get_name2", &Var::get_name2, return_value_policy<return_by_value>())
;
}
#include "module_tail.cpp"

16
test/data_members.py
View File

@@ -1,5 +1,6 @@
'''
>>> from data_members_ext import *
>>> x = X(42)
>>> x.x
42
@@ -9,13 +10,26 @@
>>> x.fair_value
42.0
>>> y = Y(69)
>>> y.x
69
>>> y.x = 77
>>> y.x
77
>>> v = Var("pi")
>>> v.value = 3.14
>>> v.name
'pi'
>>> v.name2
'pi'
>>> v.get_name1()
'pi'
>>> v.get_name2()
'pi'
'''
def run(args = None):