如何从c++;在perl中转换为哈希 我是新来的Sigg,我正在尝试将C++映射转换成Perl中的哈希。 有一个Perl扩展,使用C++需要将多维数组或映射返回到Perl。 我在swig接口文件中使用了该模板,但它给出了空结果
swig接口文件:如何从c++;在perl中转换为哈希 我是新来的Sigg,我正在尝试将C++映射转换成Perl中的哈希。 有一个Perl扩展,使用C++需要将多维数组或映射返回到Perl。 我在swig接口文件中使用了该模板,但它给出了空结果,c++,perl,swig,C++,Perl,Swig,swig接口文件: %include "exception.i" %exception { try { $action } catch (const std::exception &e) { SWIG_exception_fail(SWIG_RuntimeError, e.what()); } } %module new_tr %{ /* Put headers and other declaratio
%include "exception.i"
%exception {
try {
$action
} catch (const std::exception &e) {
SWIG_exception_fail(SWIG_RuntimeError, e.what());
}
}
%module new_tr
%{
/* Put headers and other declarations here */
#include "new_tr.h"
%}
%include <std_map.i>
%template(StringStringMap) std::map<int, std::map<std::string,std::string>>;
%include "new_tr.h"
std::map<int, std::map<std::string,std::string>> Memberfunction::m;
std::map<int, std::map<std::string,std::string>> Memberfunction::getResult()
{
return m;
}
电流输出:
$VAR1 = bless( {}, 'new_tr::StringStringMap' );
预期输出:(多维散列)
下面是一个示例,说明如何将
%typemap
用于嵌套的std::map
新的\u tr.i:
%module new_tr
%typemap(out) std::map<int, std::map<std::string,std::string>> {
HV *hash = (HV *) newHV();
for (auto const& item : $1) {
HV *subhash;
char *keysv;
auto map = item.second;
subhash = (HV *) newHV();
for (auto const &item2 : map) {
SV *sv;
auto key2 = item2.first.c_str();
auto value = item2.second.c_str();
sv = newSVpvn( value, strlen(value) );
hv_store (subhash, key2, strlen(key2), sv, 0);
}
auto key = std::to_string(item.first).c_str();
hv_store (hash, key, strlen(key), (SV*) newRV_noinc((SV*)subhash), 0);
}
$result = newRV_noinc((SV*) hash);
sv_2mortal($result);
argvi++;
}
%{
#include "new_tr.h"
%}
%include "new_tr.h"
#include <map>
#include <string>
using ssmap = std::map<int, std::map<std::string,std::string>>;
ssmap getResult();
#include "new_tr.h"
ssmap getResult()
{
ssmap map = {
{1, {{"Brown","Manager"}, {"Smith", "Salesman"}, {"Albert", "Salesman"}}},
{2, {{"Penfold", "Designer"}, {"Evans", "Tea-person"}, {"Jurgens", "Manager"}}}
};
return map;
}
use strict;
use warnings;
use Data::Dumper;
use lib '.';
use new_tr;
my $map = new_tr::getResult();
print Dumper( $map );
$VAR1 = {
'1' => {
'Albert' => 'Salesman',
'Smith' => 'Salesman',
'Brown' => 'Manager'
},
'2' => {
'Penfold' => 'Designer',
'Jurgens' => 'Manager',
'Evans' => 'Tea-person'
}
};
然后使用以下命令编译模块:
perl_include_dir=$(perl -MConfig -e'print $Config{archlib}')"/CORE"
swig -perl5 -c++ -I/usr/include new_tr.i
g++ -fPIC -c new_tr.cxx
g++ -I${perl_include_dir} -c -fPIC -g -o new_tr_wrap.o new_tr_wrap.cxx
g++ -shared -L. new_tr.o new_tr_wrap.o -o new_tr.so
然后用test.pl测试它:
%module new_tr
%typemap(out) std::map<int, std::map<std::string,std::string>> {
HV *hash = (HV *) newHV();
for (auto const& item : $1) {
HV *subhash;
char *keysv;
auto map = item.second;
subhash = (HV *) newHV();
for (auto const &item2 : map) {
SV *sv;
auto key2 = item2.first.c_str();
auto value = item2.second.c_str();
sv = newSVpvn( value, strlen(value) );
hv_store (subhash, key2, strlen(key2), sv, 0);
}
auto key = std::to_string(item.first).c_str();
hv_store (hash, key, strlen(key), (SV*) newRV_noinc((SV*)subhash), 0);
}
$result = newRV_noinc((SV*) hash);
sv_2mortal($result);
argvi++;
}
%{
#include "new_tr.h"
%}
%include "new_tr.h"
#include <map>
#include <string>
using ssmap = std::map<int, std::map<std::string,std::string>>;
ssmap getResult();
#include "new_tr.h"
ssmap getResult()
{
ssmap map = {
{1, {{"Brown","Manager"}, {"Smith", "Salesman"}, {"Albert", "Salesman"}}},
{2, {{"Penfold", "Designer"}, {"Evans", "Tea-person"}, {"Jurgens", "Manager"}}}
};
return map;
}
use strict;
use warnings;
use Data::Dumper;
use lib '.';
use new_tr;
my $map = new_tr::getResult();
print Dumper( $map );
$VAR1 = {
'1' => {
'Albert' => 'Salesman',
'Smith' => 'Salesman',
'Brown' => 'Manager'
},
'2' => {
'Penfold' => 'Designer',
'Jurgens' => 'Manager',
'Evans' => 'Tea-person'
}
};
输出:
%module new_tr
%typemap(out) std::map<int, std::map<std::string,std::string>> {
HV *hash = (HV *) newHV();
for (auto const& item : $1) {
HV *subhash;
char *keysv;
auto map = item.second;
subhash = (HV *) newHV();
for (auto const &item2 : map) {
SV *sv;
auto key2 = item2.first.c_str();
auto value = item2.second.c_str();
sv = newSVpvn( value, strlen(value) );
hv_store (subhash, key2, strlen(key2), sv, 0);
}
auto key = std::to_string(item.first).c_str();
hv_store (hash, key, strlen(key), (SV*) newRV_noinc((SV*)subhash), 0);
}
$result = newRV_noinc((SV*) hash);
sv_2mortal($result);
argvi++;
}
%{
#include "new_tr.h"
%}
%include "new_tr.h"
#include <map>
#include <string>
using ssmap = std::map<int, std::map<std::string,std::string>>;
ssmap getResult();
#include "new_tr.h"
ssmap getResult()
{
ssmap map = {
{1, {{"Brown","Manager"}, {"Smith", "Salesman"}, {"Albert", "Salesman"}}},
{2, {{"Penfold", "Designer"}, {"Evans", "Tea-person"}, {"Jurgens", "Manager"}}}
};
return map;
}
use strict;
use warnings;
use Data::Dumper;
use lib '.';
use new_tr;
my $map = new_tr::getResult();
print Dumper( $map );
$VAR1 = {
'1' => {
'Albert' => 'Salesman',
'Smith' => 'Salesman',
'Brown' => 'Manager'
},
'2' => {
'Penfold' => 'Designer',
'Jurgens' => 'Manager',
'Evans' => 'Tea-person'
}
};
在
cpp
文件中,什么是数据库
?Database::getResult
不应该是new\u tr::getResult
?同样在cpp
文件中,您返回m
,但是m
没有定义。我认为您需要为映射创建一个输出typemap
,例如%typemap(out)std::map{…}
@Håkonh230;感谢您的回复,数据库是类的成员函数,m是映射。我已经编辑了这个问题,请检查一下now@HåkonHægland感谢您的回复,我如何在swig中使用typemap将3d map转换为哈希。您的预期输出显示一个
映射,但您的代码定义了一个
映射,这是一个打字错误吗?@VinothRaja修复了typemap中的一个错误,请参阅我的更新答案。返回的散列的引用计数不应该增加,因为引用是致命的,并且在C++代码中不再需要。