C++ 在何处/如何删除创建对象的函数之外的另一个对象中的对象

为了解决这个问题，我在Valgrind下运行了整个程序，并发现了在该步骤之前发生的一些内存泄漏问题。在功能CMFLoader中发现了2个“肯定丢失”的问题

（这里MyDataset是分子对象的向量，每个分子对象包含一个Elements对象）

在CMFLoader:：loadFile（vector&MyDataset）中，我最初有

MyDataset.push_back( readMolecule( in_file, word );

其中CMFLoader:：readMolecule返回一个Molecule对象。在readmolecle函数中，创建了一个新的molecle对象（但直到main的末尾才删除，稍后将详细介绍）

其中，CMFLoader:：readFormula返回一个元素对象，并且有一个Molecule:：setFormula函数将其保存到Molecule对象。在readFormula中

Elements* CMFLoader::readFormula( stringstream& ss )
{
Elements* my_formula = new Elements();
...
return my_formula;
}

我遇到了问题中描述的问题，稍后在主程序中。具体问题发生在HammetCheck:：checkHammett步骤中。然后我将上面的CMFLoader函数更改为类似这样的函数。我之前遇到的问题似乎已经消失了（但程序中后来出现的其他问题无疑与内存泄漏有关）：

在CMFLoader:：loadFile中

Molecule* new_mol = new Molecule(word);
    MyDataset.push_back( readMolecule( in_file, word ,new_mol) );

其中readMolecule现在接受一个新的参数Molecule*，并在函数中删除新的运算符。同样，在readFormula中，我现在有

 Elements* new_formula = new Elements();
my_mol->setFormula( readFormula( ss, new_formula ) );

等等

当然，现在内存泄漏问题还没有解决！但是，I无法在任何CMFLoader函数中输入delete运算符，因为这些对象稍后将在主程序中使用。具体来说，元素*一直使用到共轭Check:：checkConjugation步骤，分子*一直使用到程序结束

主程序是这样的

int main(int argc, char* argv[]){
//initialising an empty array to store our molecules.
vector<Molecule*> MyDataset;

//Read command line inputs.
InputReader* MyInputs = new InputReader();
if( !MyInputs->readInputs(argc, argv) ) {delete MyInputs;return -1;}

//Load CMF file.
CMFLoader* MyLoader = new CMFLoader( MyInputs );
unsigned int min_same_grp = MyLoader->getmin(); //define minimum no of same hammett groups for structure
if( !MyLoader->loadFile( MyDataset ) ) {delete MyLoader;delete MyInputs;return -1;}
delete MyLoader;

cout << MyDataset.size() << " molecules loaded" << endl;

//Remove molecules which are too large.
BigFilter* MyBigFilter = new BigFilter( MyInputs );
if( !MyBigFilter->filterBigLigands( MyDataset ) ) {delete MyBigFilter;delete MyInputs;return -1;}
delete MyBigFilter;

cout << "Molecules left after big ligand filter: " << MyDataset.size() << endl;

//Mark any Hammetts groups found in molecules.
HammettCheck* MyHammettCheck = new HammettCheck(min_same_grp);
if( !MyHammettCheck->loadHammetts() ) {delete MyHammettCheck;delete MyInputs;return -1;}
if( !MyHammettCheck->checkHammett( MyDataset ) ) {delete MyHammettCheck;delete MyInputs;return -1;}
delete MyHammettCheck;

cout << "Molecules containing Hammett Groups: " << MyDataset.size() << endl;

ConjugationCheck* MyConjugationCheck = new ConjugationCheck(min_same_grp);
if( !MyConjugationCheck->checkConjugation( MyDataset ) ) {delete MyConjugationCheck;delete MyInputs;return -1;}
delete MyConjugationCheck;

cout << "Molecules containing conjugated Hammett Groups: " << MyDataset.size() << endl;

DataAdder* MyDataAdder = new DataAdder( MyInputs );
if( !MyDataAdder->addData( MyDataset ) ) {delete MyDataAdder; delete MyInputs;return -1;}
delete MyDataAdder;

//Sorts molecules based on their NLO rating given by NLOCompare.
if (min_same_grp ==1) {sort(MyDataset.begin(), MyDataset.end(), NLOCompare);}
else {sort(MyDataset.begin(), MyDataset.end(), OctuNLOCompare);}

//Saves a new CIF file containing just the predicted NLO molecules.
FileSaver* MyFileSaver = new FileSaver( MyInputs );
if( !MyFileSaver->saveFile( MyDataset ) ) {delete MyFileSaver;delete MyInputs;return -1;}
delete MyFileSaver;

/*
Saves a txt file which can be imported into Excel, showing the
paths to each of the selected Hammett groups in a molecule.
*/
ExcelSaver* MyExcelSaver = new ExcelSaver( MyInputs );
if( !MyExcelSaver->saveFile( MyDataset ) ) {delete MyExcelSaver;delete MyInputs;return -1;}
delete MyExcelSaver;

//Cleans the memory before exiting the program.
for(unsigned int i=0; i < MyDataset.size(); i++){
    delete MyDataset[i];
}
delete MyInputs;
return 0;
}

Molecule::~Molecule(void)
{
//Deletes all atoms in molecule.
for(unsigned int i=0; i < mol_atoms.size(); i++){
    delete mol_atoms[i];
}

//Deletes all bonds in molecule.
for(unsigned int i=0; i < mol_bonds.size(); i++){
    delete mol_bonds[i];
}

//Deletes the class of elements contained.
delete mol_formula;
}

这就叫分子析构函数，看起来像这样

int main(int argc, char* argv[]){
//initialising an empty array to store our molecules.
vector<Molecule*> MyDataset;

//Read command line inputs.
InputReader* MyInputs = new InputReader();
if( !MyInputs->readInputs(argc, argv) ) {delete MyInputs;return -1;}

//Load CMF file.
CMFLoader* MyLoader = new CMFLoader( MyInputs );
unsigned int min_same_grp = MyLoader->getmin(); //define minimum no of same hammett groups for structure
if( !MyLoader->loadFile( MyDataset ) ) {delete MyLoader;delete MyInputs;return -1;}
delete MyLoader;

cout << MyDataset.size() << " molecules loaded" << endl;

//Remove molecules which are too large.
BigFilter* MyBigFilter = new BigFilter( MyInputs );
if( !MyBigFilter->filterBigLigands( MyDataset ) ) {delete MyBigFilter;delete MyInputs;return -1;}
delete MyBigFilter;

cout << "Molecules left after big ligand filter: " << MyDataset.size() << endl;

//Mark any Hammetts groups found in molecules.
HammettCheck* MyHammettCheck = new HammettCheck(min_same_grp);
if( !MyHammettCheck->loadHammetts() ) {delete MyHammettCheck;delete MyInputs;return -1;}
if( !MyHammettCheck->checkHammett( MyDataset ) ) {delete MyHammettCheck;delete MyInputs;return -1;}
delete MyHammettCheck;

cout << "Molecules containing Hammett Groups: " << MyDataset.size() << endl;

ConjugationCheck* MyConjugationCheck = new ConjugationCheck(min_same_grp);
if( !MyConjugationCheck->checkConjugation( MyDataset ) ) {delete MyConjugationCheck;delete MyInputs;return -1;}
delete MyConjugationCheck;

cout << "Molecules containing conjugated Hammett Groups: " << MyDataset.size() << endl;

DataAdder* MyDataAdder = new DataAdder( MyInputs );
if( !MyDataAdder->addData( MyDataset ) ) {delete MyDataAdder; delete MyInputs;return -1;}
delete MyDataAdder;

//Sorts molecules based on their NLO rating given by NLOCompare.
if (min_same_grp ==1) {sort(MyDataset.begin(), MyDataset.end(), NLOCompare);}
else {sort(MyDataset.begin(), MyDataset.end(), OctuNLOCompare);}

//Saves a new CIF file containing just the predicted NLO molecules.
FileSaver* MyFileSaver = new FileSaver( MyInputs );
if( !MyFileSaver->saveFile( MyDataset ) ) {delete MyFileSaver;delete MyInputs;return -1;}
delete MyFileSaver;

/*
Saves a txt file which can be imported into Excel, showing the
paths to each of the selected Hammett groups in a molecule.
*/
ExcelSaver* MyExcelSaver = new ExcelSaver( MyInputs );
if( !MyExcelSaver->saveFile( MyDataset ) ) {delete MyExcelSaver;delete MyInputs;return -1;}
delete MyExcelSaver;

//Cleans the memory before exiting the program.
for(unsigned int i=0; i < MyDataset.size(); i++){
    delete MyDataset[i];
}
delete MyInputs;
return 0;
}

Molecule::~Molecule(void)
{
//Deletes all atoms in molecule.
for(unsigned int i=0; i < mol_atoms.size(); i++){
    delete mol_atoms[i];
}

//Deletes all bonds in molecule.
for(unsigned int i=0; i < mol_bonds.size(); i++){
    delete mol_bonds[i];
}

//Deletes the class of elements contained.
delete mol_formula;
}

分子：：~分子（空）
{
//删除分子中的所有原子。
for（无符号整数i=0；i

我不确定这里出了什么问题。如何解决内存泄漏问题？

Valgrind Memcheck泄漏摘要中的“绝对损失”问题

==34809== 400 (96 direct, 304 indirect) bytes in 2 blocks are definitely lost in loss record 24 of 33
==34809==    at 0x1000A0679: malloc (vg_replace_malloc.c:266)
==34809==    by 0x1000F7F04: operator new(unsigned long) (in /usr/lib/libstdc++.6.0.9.dylib)
==34809==    by 0x10000A3B4: CMFLoader::readMolecule(std::basic_ifstream<char, std::char_traits<char> >&, std::string, Molecule*) (in ./OctuDiscovery)
==34809==    by 0x10000B9EE: CMFLoader::loadFile(std::vector<Molecule*, std::allocator<Molecule*> >&) (in ./OctuDiscovery)
==34809==    by 0x10000282E: main (in ./OctuDiscovery)

==34809== 12,833 (152 direct, 12,681 indirect) bytes in 1 blocks are definitely lost in loss record 33 of 33
==34809==    at 0x1000A0679: malloc (vg_replace_malloc.c:266)
==34809==    by 0x1000F7F04: operator new(unsigned long) (in /usr/lib/libstdc++.6.0.9.dylib)
==34809==    by 0x10000B93B: CMFLoader::loadFile(std::vector<Molecule*, std::allocator<Molecule*> >&) (in ./OctuDiscovery)
==34809==    by 0x10000282E: main (in ./OctuDiscovery)

==34809==400（96个直接字节，304个间接字节）两个块中的字节肯定会在33个块中的24个丢失记录中丢失
==34809==0x1000A0679:malloc（vg_替换_malloc.c:266）
==34809==by 0x1000F7F04:运算符新（无符号长）（in/usr/lib/libstdc++.6.0.9.dylib）
==34809==0x10000A3B4:CMFLoader:：readMolecule（std:：basic_ifstream&，std:：string，Molecule*）（in./OctuDiscovery）
==34809==by 0x10000B9EE:CMFLoader:：loadFile（std:：vector&）（in./OctuDiscovery）
==34809==0x10000282E:main（in./OctuDiscovery）
==34809==12833（152个直接字节，12681个间接字节）1个块中的字节肯定会在33个块中的丢失记录33中丢失
==34809==0x1000A0679:malloc（vg_替换_malloc.c:266）
==34809==by 0x1000F7F04:运算符新（无符号长）（in/usr/lib/libstdc++.6.0.9.dylib）
==34809==0x10000B93B:CMFLoader:：loadFile（std:：vector&）（in./OctuDiscovery）
==34809==0x10000282E:main（in./OctuDiscovery）

如果您想做这样的事情，我建议您看看std:：auto_ptr类，或者至少看看智能指针或自动指针的概念。您应该依赖RAII（Resource Aquisition Is Initialization）范式，这意味着内存管理应该由对象本身完成：尽可能避免使用基本指针和自行编写的内存管理代码

如果您想做这样的事情，我建议您看看std:：auto_ptr类，或者至少看看智能指针或自动指针的概念。您应该依赖RAII（Resource Aquisition Is Initialization）范式，这意味着内存管理应该由对象本身完成：尽可能避免使用基本指针和自行编写的内存管理代码

与其说是回答，不如说是评论，但评论太长：
在下一个函数中，使用动态内存没有意义：

Molecule* CMFLoader::readMolecule( ifstream& in_file, string id)
{
Molecule* my_mol = new Molecule( id );
// statements, somewhere along the readFormula function is called
my_mol->setFormula( readFormula( ss ) );
return my_mol;
}

您可以将其替换为：

Molecule CMFLoader::readMolecule( ifstream& in_file, string id)
{
Molecule my_mol( id );
// statements, somewhere along the readFormula function is called
my_mol.setFormula( readFormula( ss ) );
return my_mol;
}

---

这已经解决了1个可能的内存泄漏问题，但可能有需要/首选动态内存版本的原因，在这种情况下，应该使用已经提到的唯一\u ptr。

与其说是答案，不如说是注释：
在下一个函数中，使用动态内存没有意义：

Molecule* CMFLoader::readMolecule( ifstream& in_file, string id)
{
Molecule* my_mol = new Molecule( id );
// statements, somewhere along the readFormula function is called
my_mol->setFormula( readFormula( ss ) );
return my_mol;
}

您可以将其替换为：

Molecule CMFLoader::readMolecule( ifstream& in_file, string id)
{
Molecule my_mol( id );
// statements, somewhere along the readFormula function is called
my_mol.setFormula( readFormula( ss ) );
return my_mol;
}

---

这已经解决了1个可能的内存泄漏问题，但可能有理由需要/首选动态内存版本，在这种情况下，应该使用前面提到的unique\u ptr。

这需要大量的

delete

so\o。您应该阅读RAII，特别是

unique\u ptr

。所有资源都应该由负责其生命周期的自动对象拥有。使用类型系统确保没有任何泄漏。@Mankarse我看到unique_ptr是c++11实现？如果我使用的是gcc4.2编译器，我应该改用auto_ptr吗？@幻灭：您可以使用

auto_ptr

，或者您可以使用，或者您可以使用自己的

unique_ptr

，或者您可以停止对尽可能多的事情使用动态分配——您在

main

中构造的任何对象都完全不需要它，例如（或者你所展示的代码中的任何地方），同样，你在最后说，从

向量

上弹出一个

分子*

将调用它的析构函数。我敢肯定不会的。如果它是一个

向量

，它就会出现。这很可能是导致内存泄漏的原因。@dogmative所以，如果我先调用析构函数，然后再弹出向量，这可能会解决我的问题吗？说replace MyDataset.pop_back（）；使用delete MyDataset[i]；MyDataset.erase（MyDataset