Override C++ - кто знает, помогите

[VISTALL]

Есть код

[src=#cpp]
/*
* Copyright 2010-2011 napile
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once

#include <string>
#include <vector>
#include "config.h"

class ClasspathEntry
{
protected:
std:tring _path;
public:
ClasspathEntry();

virtual void addToClassPath(std::vector<std:tring> list) ;
};
[/src]

[src=#cpp]
/*
* Copyright 2010-2011 napile
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include "ClasspathEntry.h"

class ClasspathDirectory : public ClasspathEntry
{
public:
std:tring _pattern;

ClasspathDirectory(std:tring path, std:tring patt);

void addToClassPath(std::vector<std:tring> list) override;
};
[/src]



и есть метод

[src=#cpp]
void JVMOptions::initClasspath()
{
_classpath.push_back(ClasspathDirectory("lib", "*"));

DEBUG("------------------------------------------------------------------");
DEBUG("Calling initClasspath " + StringUtils::toString(_classpath.size()));

std::vector<std:tring> list;

for(int i = 0; i < _classpath.size(); i++)
{
ClasspathEntry entry = _classpath[i];

entry.addToClassPath(list);
}

DEBUG("------------------------------------------------------------------");
}

[/src]



Итог я получаю
[src=#cpp]
void ClasspathEntry::addToClassPath(std::vector<std:tring> list)
{
DEBUG("Calling ClasspathEntry.addToClassPath");
}
[/src]


Как сделать что б вызывалось с детей, entry.addToClassPath(list);, а не с матери

Добавлено через 3 минуты
Ах да реализация
[src=#cpp]
/*
* Copyright 2010-2011 napile
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "ClasspathDirectory.h"
#include "FileUtils.h"
#include "common.h"


ClasspathDirectory::ClasspathDirectory(std:tring path, std:tring patt)
{
_path = path;
_pattern = patt;
}

void ClasspathDirectory::addToClassPath(std::vector<std:tring> list)
{
std:tring currentPath = std:tring(EXE_MAKER_CURRENT_DIR);

if (!FileUtils::isAbsolute(currentPath))
currentPath = FileUtils::concFile(FileUtils::getExecutablePath(), currentPath);

DEBUG("Path to search " + currentPath + "; pattern " + _pattern);
}

[/src]

[hex1r0]

динамически создавай обьект и вызывай через указатель
T *obj = new T(...);
obj->myVirtualMethod();

[VISTALL]

динамически создавай обьект и вызывай через указатель

код посмотри

void JVMOptions::initClasspath() метод

просто там не один наследник

[hex1r0]

псевдокод (не тестировал) (вектор будет сохранять указатели)

Код:

_classpath.push_back(new ClasspathDirectory("lib", "*"));

    DEBUG("------------------------------------------------------------------");
    DEBUG("Calling initClasspath " + StringUtils::toString(_classpath.size()));

    std::vector<std::string> list;

    for(int i = 0; i < _classpath.size(); i++)
    {
        ClasspathEntry *entry = _classpath[i];

        entry->addToClassPath(list);
    }

    DEBUG("------------------------------------------------------------------");

[VISTALL]

как бы, std::vector<ClasspathEntry> _classpath;

Добавлено через 3 минуты
и сменой шаблона как бы, не изменит ситуацию

[hex1r0]

http://developer.kde.org/~wheeler/cpp-pitfalls.html

111

virtual Methods
virtual methods are an essential part of designing a class hierarchy and subclassing classes from a toolkit. The concept is relatively simple, but often misunderstood. Specifically it determines the behavior of overridden methods in certain contexts.

By placing the keyword virtual before a method declaration it says that when referring to an instance of a superclass by a pointer or reference to a base class that the correct implementation should be resolved at run time and that the "highest level" implementation should be used.

Again, this should be more clear with an example:

class Foo
{
public:
void f()
{
std::cout << "Foo::f()" << std::endl;
}
virtual void g()
{
std::cout << "Foo::g()" << std::endl;
}
};

class Bar : public Foo
{
public:
void f()
{
std::cout << "Bar::f()" << std::endl;
}
virtual void g()
{
std::cout << "Bar::g()" << std::endl;
}
};

int main()
{
Foo foo;
Bar bar;

Foo *baz = &bar;
Bar *quux = &bar;

foo.f(); // "Foo::f()"
foo.g(); // "Foo::g()"

bar.f(); // "Bar::f()"
bar.g(); // "Bar::g()"

// So far everything we would expect...

baz->f(); // "Foo::f()"
baz->g(); // "Bar::g()"

quux->f(); // "Bar::f()"
quux->g(); // "Bar::g()"

return 0;
}

Our first calls to f() and g() on the two objects are straightforward. However things get interesting with our baz pointer which is a pointer to the Foo type.

f() is not virtual and as such a call to f() will always invoke the implementation associated with the pointer type — in this case the implementation from Foo.

[VISTALL]

Странно то что я сделал так, ток ниче не дало

[hex1r0]

std::vector<ClasspathEntry*> _classpath; ?

[Array]

Хм, у меня заработало. Не ожидал такого (:
[src=c++]
A ** data;
data = new A*[2];

B b; b.f(); // b
C c; c.f(); // c

data[0] = &b;
data[0]->f(); // b
[/src]

[VISTALL]

std::vector<ClasspathEntry*> _classpath; ?

спс)

итог

std::vector<ClasspathEntry*> _classpath;

[src=cpp]
void JVMOptions::initClasspath()
{
_classpath.push_back(&ClasspathDirectory("lib", "*"));

DEBUG("------------------------------------------------------------------");
DEBUG("Calling initClasspath " + StringUtils::toString(_classpath.size()));

std::vector<std:tring> list;

for(int i = 0; i < _classpath.size(); i++)
{
ClasspathEntry *entry = _classpath[i];

entry->addToClassPath(list);
}

DEBUG("------------------------------------------------------------------");
}
[/src]

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