Swig包装了C ++数据类型？

Question

This might be an easy question. How I can call c++ defined datatype UInt32 from python?

test.cpp:

#include "test.h"
namespace test {  
    void test(UInt32 param) { std::cout << param << std::endl; }
}

test.h:

#include <ios>
#include <vector>
#include <string>
#include <algorithm>
#include <iostream>
#include <assert.h>
#include <cassert>
#include <cstddef>
#include <stddef.h>
namespace test {
    typedef std::uint32_t UInt32;
    void test(UInt32 param);
}

test.i:

%module test
%{
    #define SWIG_FILE_WITH_INIT
    #include "test.h"
%}
%include "test.h"    

error:

>>> import test
>>> test.test(1)
TypeError: in method 'test', argument 1 of type 'test::UInt32'

Answer 1

Use typemapping ( link ). The simplest should look like:

%apply int { test::UInt32 };  

Answer 2

The problem here is that SWIG doesn't know what a type UInt32 "is." For a normal C++ typedef, you can simply tell SWIG in your interface file using the %typedef command , eg:

%inline %{
 typedef unsigned int size_t;
%}

The above solution, ie, %apply int{ UInt32 }; is essentially using the SWIG typemaps library ( Typemaps.i ) to replace any instance of the argument of form UInt32 with int (which SWIG knows about by default). However, it doesn't necessarily preserve the unsigned properties. Here you may want to instead use %apply unsigned int { UInt32 }; . (Note that you need to include Typemaps.i for this to work).

Finally, if you need to be able to return the value (eg, you want to pass it by reference), you can use the form:

%apply unsigned int *INOUT { UInt32 };

The way to go depends upon what you want to do. If you just need SWIG to understand a typedef as a "synonym" of a (primitive or derived) type SWIG already knows about, the typedef approach is sufficient. If you also need to control the behavior of how SWIG handles arguments (eg, you need to be able to pass/return values by reference), typemaps (provided by the %apply command) is the way to go.