Second iterator overwrites first iterator [closed]
I am not (yet) a good coder in C++ and I am working through some tasks from a training book, where I wrote a class for IP-addresses. In this class I have a private vector<string>
which saves the single blocks of the address.
I overloaded the == operator
and here I hand over the object that I want to compare to by reference.
I have a vector::iterator
for the this-object
. I have now the problem that my second iterator that I defined for the compareTo-object
overwrites the first iterator.
I have been searching for the mistake for hours. Please find the code snippet and its output attached. Any ideas? Or is this intended behavior of C++? I use CLANG-compiler on MacOS.
from Class IPv4
class IPv4
{
private:
string adress;
vector<string> IPBlocksOfAdress;
bool testIP();
vector<string> splitString(const string stringToSplit, char delimiter = '.');
public:
IPv4::IPv4(const string &inputAdress)
{
setAdress(inputAdress);
}
bool IPv4::testIP()
{
bool isIP = true;
for (vector<string>::iterator blocksOfAdressIterator = IPBlocksOfAdress.begin();
blocksOfAdressIterator != IPBlocksOfAdress.end(); blocksOfAdressIterator++) {
if (stoi(*blocksOfAdressIterator) > 255 || stoi(*blocksOfAdressIterator) < 0) {
isIP = false;
}
}
return isIP;
}
vector<string> IPv4::splitString(const string stringToSplit, char delimiter)
{
vector<string> blocksOfAdress;
stringstream stringToSplitStream(stringToSplit);
string blockOfAdress = "";
while (getline(stringToSplitStream, blockOfAdress, delimiter)) {
blocksOfAdress.push_back(blockOfAdress);
}
return blocksOfAdress;
}
string IPv4::getAdress() const
{
if (adress != "0.0.0.0") {
return adress;
} else {
return "Error, Adress not set.";
}
}
vector<string> IPv4::getAdressBlocks() const
{
return IPBlocksOfAdress;
}
void IPv4::setAdress(const string &inputAdress)
{
IPBlocksOfAdress = splitString(inputAdress,'.');
if (testIP()) {
cout << "Neue IP Addresse: " << inputAdress << endl;
adress = inputAdress;
} else {
cout << "Die Eingabe entspricht nicht dem IPv4-Format. Setze Adresse auf 0.0.0.0" << endl;
adress = "0.0.0.0";
IPBlocksOfAdress = splitString(adress,'.');
}
}
bool IPv4::operator == (const IPv4 &compareTo) const
{
cout << " ... in operator == ..." << endl;
bool isIdenticalThis = true;
cout << "this Adress: " << this->getAdress() << endl;
cout << "compareTo Adress: " << compareTo.getAdress() << endl;
vector<string>::iterator adressBlockThis = this->getAdressBlocks().begin();
cout << "this first block: " << *adressBlockThis << endl;
vector<string>::iterator adressBlockCompareTo = compareTo.getAdressBlocks().begin();
cout << "compareTo first block: " << *adressBlockCompareTo << endl;
cout << "this first block second printout: " << *adressBlockThis << endl;
...
}
from main:
IPv4 myIP("1.2.3.4");
cout << "Get IP: " << myIP.getAdress() << endl;
IPv4 mySecondIP("5.6.7.8");
cout << "Get IP: " << mySecondIP.getAdress() << endl;
cout << myIP.getAdress() << " == " << mySecondIP.getAdress()
<< " = " << (myIP == mySecondIP) << endl;
output console:
Neue IP Addresse: 1.2.3.4
Get IP: 1.2.3.4
Neue IP Addresse: 5.6.7.8
Get IP: 5.6.7.8
1.2.3.4 == 5.6.7.8 =
... in operator == ...
this Adress: 1.2.3.4
compareTo Adress: 5.6.7.8
this first block: 1
compareTo first block: 5
this first block second printout: 5 <------- this should be 1
1
c++ iterator operator-overloading stdvector overwrite
closed as off-topic by Neil Butterworth, πάντα ῥεῖ, user4581301, Swordfish, gnat Nov 23 '18 at 23:09
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions seeking debugging help ("why isn't this code working?") must include the desired behavior, a specific problem or error and the shortest code necessary to reproduce it in the question itself. Questions without a clear problem statement are not useful to other readers. See: How to create a Minimal, Complete, and Verifiable example." – πάντα ῥεῖ, user4581301, Swordfish
If this question can be reworded to fit the rules in the help center, please edit the question.
|
show 4 more comments
I am not (yet) a good coder in C++ and I am working through some tasks from a training book, where I wrote a class for IP-addresses. In this class I have a private vector<string>
which saves the single blocks of the address.
I overloaded the == operator
and here I hand over the object that I want to compare to by reference.
I have a vector::iterator
for the this-object
. I have now the problem that my second iterator that I defined for the compareTo-object
overwrites the first iterator.
I have been searching for the mistake for hours. Please find the code snippet and its output attached. Any ideas? Or is this intended behavior of C++? I use CLANG-compiler on MacOS.
from Class IPv4
class IPv4
{
private:
string adress;
vector<string> IPBlocksOfAdress;
bool testIP();
vector<string> splitString(const string stringToSplit, char delimiter = '.');
public:
IPv4::IPv4(const string &inputAdress)
{
setAdress(inputAdress);
}
bool IPv4::testIP()
{
bool isIP = true;
for (vector<string>::iterator blocksOfAdressIterator = IPBlocksOfAdress.begin();
blocksOfAdressIterator != IPBlocksOfAdress.end(); blocksOfAdressIterator++) {
if (stoi(*blocksOfAdressIterator) > 255 || stoi(*blocksOfAdressIterator) < 0) {
isIP = false;
}
}
return isIP;
}
vector<string> IPv4::splitString(const string stringToSplit, char delimiter)
{
vector<string> blocksOfAdress;
stringstream stringToSplitStream(stringToSplit);
string blockOfAdress = "";
while (getline(stringToSplitStream, blockOfAdress, delimiter)) {
blocksOfAdress.push_back(blockOfAdress);
}
return blocksOfAdress;
}
string IPv4::getAdress() const
{
if (adress != "0.0.0.0") {
return adress;
} else {
return "Error, Adress not set.";
}
}
vector<string> IPv4::getAdressBlocks() const
{
return IPBlocksOfAdress;
}
void IPv4::setAdress(const string &inputAdress)
{
IPBlocksOfAdress = splitString(inputAdress,'.');
if (testIP()) {
cout << "Neue IP Addresse: " << inputAdress << endl;
adress = inputAdress;
} else {
cout << "Die Eingabe entspricht nicht dem IPv4-Format. Setze Adresse auf 0.0.0.0" << endl;
adress = "0.0.0.0";
IPBlocksOfAdress = splitString(adress,'.');
}
}
bool IPv4::operator == (const IPv4 &compareTo) const
{
cout << " ... in operator == ..." << endl;
bool isIdenticalThis = true;
cout << "this Adress: " << this->getAdress() << endl;
cout << "compareTo Adress: " << compareTo.getAdress() << endl;
vector<string>::iterator adressBlockThis = this->getAdressBlocks().begin();
cout << "this first block: " << *adressBlockThis << endl;
vector<string>::iterator adressBlockCompareTo = compareTo.getAdressBlocks().begin();
cout << "compareTo first block: " << *adressBlockCompareTo << endl;
cout << "this first block second printout: " << *adressBlockThis << endl;
...
}
from main:
IPv4 myIP("1.2.3.4");
cout << "Get IP: " << myIP.getAdress() << endl;
IPv4 mySecondIP("5.6.7.8");
cout << "Get IP: " << mySecondIP.getAdress() << endl;
cout << myIP.getAdress() << " == " << mySecondIP.getAdress()
<< " = " << (myIP == mySecondIP) << endl;
output console:
Neue IP Addresse: 1.2.3.4
Get IP: 1.2.3.4
Neue IP Addresse: 5.6.7.8
Get IP: 5.6.7.8
1.2.3.4 == 5.6.7.8 =
... in operator == ...
this Adress: 1.2.3.4
compareTo Adress: 5.6.7.8
this first block: 1
compareTo first block: 5
this first block second printout: 5 <------- this should be 1
1
c++ iterator operator-overloading stdvector overwrite
closed as off-topic by Neil Butterworth, πάντα ῥεῖ, user4581301, Swordfish, gnat Nov 23 '18 at 23:09
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions seeking debugging help ("why isn't this code working?") must include the desired behavior, a specific problem or error and the shortest code necessary to reproduce it in the question itself. Questions without a clear problem statement are not useful to other readers. See: How to create a Minimal, Complete, and Verifiable example." – πάντα ῥεῖ, user4581301, Swordfish
If this question can be reworded to fit the rules in the help center, please edit the question.
Perhaps, but where is the code that makes the operation? Not int he question.
– Matthieu Brucher
Nov 23 '18 at 21:28
I'm afraid you have left too many possibilities open. I recommend crafting a Minimal, Complete, and Verifiable example. If making the MCVE doesn't reveal the problem and solution to you, and it usually does, edit the question to add the MCVE.
– user4581301
Nov 23 '18 at 21:33
You are right, not enough information. So I attached the rest:
– TheFox
Nov 23 '18 at 21:36
Still missing some: specifically, the implementation ofgetAddressBlocks
– Sebastian Redl
Nov 23 '18 at 21:41
@TheFox You added prose, no Minimal, Complete, and Verifiable example.
– Swordfish
Nov 23 '18 at 21:42
|
show 4 more comments
I am not (yet) a good coder in C++ and I am working through some tasks from a training book, where I wrote a class for IP-addresses. In this class I have a private vector<string>
which saves the single blocks of the address.
I overloaded the == operator
and here I hand over the object that I want to compare to by reference.
I have a vector::iterator
for the this-object
. I have now the problem that my second iterator that I defined for the compareTo-object
overwrites the first iterator.
I have been searching for the mistake for hours. Please find the code snippet and its output attached. Any ideas? Or is this intended behavior of C++? I use CLANG-compiler on MacOS.
from Class IPv4
class IPv4
{
private:
string adress;
vector<string> IPBlocksOfAdress;
bool testIP();
vector<string> splitString(const string stringToSplit, char delimiter = '.');
public:
IPv4::IPv4(const string &inputAdress)
{
setAdress(inputAdress);
}
bool IPv4::testIP()
{
bool isIP = true;
for (vector<string>::iterator blocksOfAdressIterator = IPBlocksOfAdress.begin();
blocksOfAdressIterator != IPBlocksOfAdress.end(); blocksOfAdressIterator++) {
if (stoi(*blocksOfAdressIterator) > 255 || stoi(*blocksOfAdressIterator) < 0) {
isIP = false;
}
}
return isIP;
}
vector<string> IPv4::splitString(const string stringToSplit, char delimiter)
{
vector<string> blocksOfAdress;
stringstream stringToSplitStream(stringToSplit);
string blockOfAdress = "";
while (getline(stringToSplitStream, blockOfAdress, delimiter)) {
blocksOfAdress.push_back(blockOfAdress);
}
return blocksOfAdress;
}
string IPv4::getAdress() const
{
if (adress != "0.0.0.0") {
return adress;
} else {
return "Error, Adress not set.";
}
}
vector<string> IPv4::getAdressBlocks() const
{
return IPBlocksOfAdress;
}
void IPv4::setAdress(const string &inputAdress)
{
IPBlocksOfAdress = splitString(inputAdress,'.');
if (testIP()) {
cout << "Neue IP Addresse: " << inputAdress << endl;
adress = inputAdress;
} else {
cout << "Die Eingabe entspricht nicht dem IPv4-Format. Setze Adresse auf 0.0.0.0" << endl;
adress = "0.0.0.0";
IPBlocksOfAdress = splitString(adress,'.');
}
}
bool IPv4::operator == (const IPv4 &compareTo) const
{
cout << " ... in operator == ..." << endl;
bool isIdenticalThis = true;
cout << "this Adress: " << this->getAdress() << endl;
cout << "compareTo Adress: " << compareTo.getAdress() << endl;
vector<string>::iterator adressBlockThis = this->getAdressBlocks().begin();
cout << "this first block: " << *adressBlockThis << endl;
vector<string>::iterator adressBlockCompareTo = compareTo.getAdressBlocks().begin();
cout << "compareTo first block: " << *adressBlockCompareTo << endl;
cout << "this first block second printout: " << *adressBlockThis << endl;
...
}
from main:
IPv4 myIP("1.2.3.4");
cout << "Get IP: " << myIP.getAdress() << endl;
IPv4 mySecondIP("5.6.7.8");
cout << "Get IP: " << mySecondIP.getAdress() << endl;
cout << myIP.getAdress() << " == " << mySecondIP.getAdress()
<< " = " << (myIP == mySecondIP) << endl;
output console:
Neue IP Addresse: 1.2.3.4
Get IP: 1.2.3.4
Neue IP Addresse: 5.6.7.8
Get IP: 5.6.7.8
1.2.3.4 == 5.6.7.8 =
... in operator == ...
this Adress: 1.2.3.4
compareTo Adress: 5.6.7.8
this first block: 1
compareTo first block: 5
this first block second printout: 5 <------- this should be 1
1
c++ iterator operator-overloading stdvector overwrite
I am not (yet) a good coder in C++ and I am working through some tasks from a training book, where I wrote a class for IP-addresses. In this class I have a private vector<string>
which saves the single blocks of the address.
I overloaded the == operator
and here I hand over the object that I want to compare to by reference.
I have a vector::iterator
for the this-object
. I have now the problem that my second iterator that I defined for the compareTo-object
overwrites the first iterator.
I have been searching for the mistake for hours. Please find the code snippet and its output attached. Any ideas? Or is this intended behavior of C++? I use CLANG-compiler on MacOS.
from Class IPv4
class IPv4
{
private:
string adress;
vector<string> IPBlocksOfAdress;
bool testIP();
vector<string> splitString(const string stringToSplit, char delimiter = '.');
public:
IPv4::IPv4(const string &inputAdress)
{
setAdress(inputAdress);
}
bool IPv4::testIP()
{
bool isIP = true;
for (vector<string>::iterator blocksOfAdressIterator = IPBlocksOfAdress.begin();
blocksOfAdressIterator != IPBlocksOfAdress.end(); blocksOfAdressIterator++) {
if (stoi(*blocksOfAdressIterator) > 255 || stoi(*blocksOfAdressIterator) < 0) {
isIP = false;
}
}
return isIP;
}
vector<string> IPv4::splitString(const string stringToSplit, char delimiter)
{
vector<string> blocksOfAdress;
stringstream stringToSplitStream(stringToSplit);
string blockOfAdress = "";
while (getline(stringToSplitStream, blockOfAdress, delimiter)) {
blocksOfAdress.push_back(blockOfAdress);
}
return blocksOfAdress;
}
string IPv4::getAdress() const
{
if (adress != "0.0.0.0") {
return adress;
} else {
return "Error, Adress not set.";
}
}
vector<string> IPv4::getAdressBlocks() const
{
return IPBlocksOfAdress;
}
void IPv4::setAdress(const string &inputAdress)
{
IPBlocksOfAdress = splitString(inputAdress,'.');
if (testIP()) {
cout << "Neue IP Addresse: " << inputAdress << endl;
adress = inputAdress;
} else {
cout << "Die Eingabe entspricht nicht dem IPv4-Format. Setze Adresse auf 0.0.0.0" << endl;
adress = "0.0.0.0";
IPBlocksOfAdress = splitString(adress,'.');
}
}
bool IPv4::operator == (const IPv4 &compareTo) const
{
cout << " ... in operator == ..." << endl;
bool isIdenticalThis = true;
cout << "this Adress: " << this->getAdress() << endl;
cout << "compareTo Adress: " << compareTo.getAdress() << endl;
vector<string>::iterator adressBlockThis = this->getAdressBlocks().begin();
cout << "this first block: " << *adressBlockThis << endl;
vector<string>::iterator adressBlockCompareTo = compareTo.getAdressBlocks().begin();
cout << "compareTo first block: " << *adressBlockCompareTo << endl;
cout << "this first block second printout: " << *adressBlockThis << endl;
...
}
from main:
IPv4 myIP("1.2.3.4");
cout << "Get IP: " << myIP.getAdress() << endl;
IPv4 mySecondIP("5.6.7.8");
cout << "Get IP: " << mySecondIP.getAdress() << endl;
cout << myIP.getAdress() << " == " << mySecondIP.getAdress()
<< " = " << (myIP == mySecondIP) << endl;
output console:
Neue IP Addresse: 1.2.3.4
Get IP: 1.2.3.4
Neue IP Addresse: 5.6.7.8
Get IP: 5.6.7.8
1.2.3.4 == 5.6.7.8 =
... in operator == ...
this Adress: 1.2.3.4
compareTo Adress: 5.6.7.8
this first block: 1
compareTo first block: 5
this first block second printout: 5 <------- this should be 1
1
c++ iterator operator-overloading stdvector overwrite
c++ iterator operator-overloading stdvector overwrite
edited Nov 23 '18 at 22:32
bcperth
2,0011514
2,0011514
asked Nov 23 '18 at 21:23
TheFoxTheFox
34
34
closed as off-topic by Neil Butterworth, πάντα ῥεῖ, user4581301, Swordfish, gnat Nov 23 '18 at 23:09
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions seeking debugging help ("why isn't this code working?") must include the desired behavior, a specific problem or error and the shortest code necessary to reproduce it in the question itself. Questions without a clear problem statement are not useful to other readers. See: How to create a Minimal, Complete, and Verifiable example." – πάντα ῥεῖ, user4581301, Swordfish
If this question can be reworded to fit the rules in the help center, please edit the question.
closed as off-topic by Neil Butterworth, πάντα ῥεῖ, user4581301, Swordfish, gnat Nov 23 '18 at 23:09
This question appears to be off-topic. The users who voted to close gave this specific reason:
- "Questions seeking debugging help ("why isn't this code working?") must include the desired behavior, a specific problem or error and the shortest code necessary to reproduce it in the question itself. Questions without a clear problem statement are not useful to other readers. See: How to create a Minimal, Complete, and Verifiable example." – πάντα ῥεῖ, user4581301, Swordfish
If this question can be reworded to fit the rules in the help center, please edit the question.
Perhaps, but where is the code that makes the operation? Not int he question.
– Matthieu Brucher
Nov 23 '18 at 21:28
I'm afraid you have left too many possibilities open. I recommend crafting a Minimal, Complete, and Verifiable example. If making the MCVE doesn't reveal the problem and solution to you, and it usually does, edit the question to add the MCVE.
– user4581301
Nov 23 '18 at 21:33
You are right, not enough information. So I attached the rest:
– TheFox
Nov 23 '18 at 21:36
Still missing some: specifically, the implementation ofgetAddressBlocks
– Sebastian Redl
Nov 23 '18 at 21:41
@TheFox You added prose, no Minimal, Complete, and Verifiable example.
– Swordfish
Nov 23 '18 at 21:42
|
show 4 more comments
Perhaps, but where is the code that makes the operation? Not int he question.
– Matthieu Brucher
Nov 23 '18 at 21:28
I'm afraid you have left too many possibilities open. I recommend crafting a Minimal, Complete, and Verifiable example. If making the MCVE doesn't reveal the problem and solution to you, and it usually does, edit the question to add the MCVE.
– user4581301
Nov 23 '18 at 21:33
You are right, not enough information. So I attached the rest:
– TheFox
Nov 23 '18 at 21:36
Still missing some: specifically, the implementation ofgetAddressBlocks
– Sebastian Redl
Nov 23 '18 at 21:41
@TheFox You added prose, no Minimal, Complete, and Verifiable example.
– Swordfish
Nov 23 '18 at 21:42
Perhaps, but where is the code that makes the operation? Not int he question.
– Matthieu Brucher
Nov 23 '18 at 21:28
Perhaps, but where is the code that makes the operation? Not int he question.
– Matthieu Brucher
Nov 23 '18 at 21:28
I'm afraid you have left too many possibilities open. I recommend crafting a Minimal, Complete, and Verifiable example. If making the MCVE doesn't reveal the problem and solution to you, and it usually does, edit the question to add the MCVE.
– user4581301
Nov 23 '18 at 21:33
I'm afraid you have left too many possibilities open. I recommend crafting a Minimal, Complete, and Verifiable example. If making the MCVE doesn't reveal the problem and solution to you, and it usually does, edit the question to add the MCVE.
– user4581301
Nov 23 '18 at 21:33
You are right, not enough information. So I attached the rest:
– TheFox
Nov 23 '18 at 21:36
You are right, not enough information. So I attached the rest:
– TheFox
Nov 23 '18 at 21:36
Still missing some: specifically, the implementation of
getAddressBlocks
– Sebastian Redl
Nov 23 '18 at 21:41
Still missing some: specifically, the implementation of
getAddressBlocks
– Sebastian Redl
Nov 23 '18 at 21:41
@TheFox You added prose, no Minimal, Complete, and Verifiable example.
– Swordfish
Nov 23 '18 at 21:42
@TheFox You added prose, no Minimal, Complete, and Verifiable example.
– Swordfish
Nov 23 '18 at 21:42
|
show 4 more comments
1 Answer
1
active
oldest
votes
Your iterator isn't being "overwritten", it's being invalidated. It's dangling. Both of them are.
The numbers you see are pure chance. (Well, they aren't; we can reason about why you're seeing them to some degree, and in this case it's pretty obvious where they come from, but undefined behaviour is undefined behaviour and it's best to just leave it at that.)
getAdressBlocks
should return a reference to the existing vector. The value/copy it's returning now dies pretty much immediately, leaving you with an iterator pointing to the first element of something that no longer exists.
You're calling this function through a const IPv4&
so it will have to (and should) return a const
reference:
const vector<string>& IPv4::getAdressBlocks() const
{
return IPBlocksOfAdress;
}
This also means though that your iterators will have to be vector<string>::const_iterator
.
And you've misspelt "address" throughout.
For the "Address" thing. I mixed up German and English. In German it is Adresse in Englisch it is address.
– TheFox
Nov 24 '18 at 8:34
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Your iterator isn't being "overwritten", it's being invalidated. It's dangling. Both of them are.
The numbers you see are pure chance. (Well, they aren't; we can reason about why you're seeing them to some degree, and in this case it's pretty obvious where they come from, but undefined behaviour is undefined behaviour and it's best to just leave it at that.)
getAdressBlocks
should return a reference to the existing vector. The value/copy it's returning now dies pretty much immediately, leaving you with an iterator pointing to the first element of something that no longer exists.
You're calling this function through a const IPv4&
so it will have to (and should) return a const
reference:
const vector<string>& IPv4::getAdressBlocks() const
{
return IPBlocksOfAdress;
}
This also means though that your iterators will have to be vector<string>::const_iterator
.
And you've misspelt "address" throughout.
For the "Address" thing. I mixed up German and English. In German it is Adresse in Englisch it is address.
– TheFox
Nov 24 '18 at 8:34
add a comment |
Your iterator isn't being "overwritten", it's being invalidated. It's dangling. Both of them are.
The numbers you see are pure chance. (Well, they aren't; we can reason about why you're seeing them to some degree, and in this case it's pretty obvious where they come from, but undefined behaviour is undefined behaviour and it's best to just leave it at that.)
getAdressBlocks
should return a reference to the existing vector. The value/copy it's returning now dies pretty much immediately, leaving you with an iterator pointing to the first element of something that no longer exists.
You're calling this function through a const IPv4&
so it will have to (and should) return a const
reference:
const vector<string>& IPv4::getAdressBlocks() const
{
return IPBlocksOfAdress;
}
This also means though that your iterators will have to be vector<string>::const_iterator
.
And you've misspelt "address" throughout.
For the "Address" thing. I mixed up German and English. In German it is Adresse in Englisch it is address.
– TheFox
Nov 24 '18 at 8:34
add a comment |
Your iterator isn't being "overwritten", it's being invalidated. It's dangling. Both of them are.
The numbers you see are pure chance. (Well, they aren't; we can reason about why you're seeing them to some degree, and in this case it's pretty obvious where they come from, but undefined behaviour is undefined behaviour and it's best to just leave it at that.)
getAdressBlocks
should return a reference to the existing vector. The value/copy it's returning now dies pretty much immediately, leaving you with an iterator pointing to the first element of something that no longer exists.
You're calling this function through a const IPv4&
so it will have to (and should) return a const
reference:
const vector<string>& IPv4::getAdressBlocks() const
{
return IPBlocksOfAdress;
}
This also means though that your iterators will have to be vector<string>::const_iterator
.
And you've misspelt "address" throughout.
Your iterator isn't being "overwritten", it's being invalidated. It's dangling. Both of them are.
The numbers you see are pure chance. (Well, they aren't; we can reason about why you're seeing them to some degree, and in this case it's pretty obvious where they come from, but undefined behaviour is undefined behaviour and it's best to just leave it at that.)
getAdressBlocks
should return a reference to the existing vector. The value/copy it's returning now dies pretty much immediately, leaving you with an iterator pointing to the first element of something that no longer exists.
You're calling this function through a const IPv4&
so it will have to (and should) return a const
reference:
const vector<string>& IPv4::getAdressBlocks() const
{
return IPBlocksOfAdress;
}
This also means though that your iterators will have to be vector<string>::const_iterator
.
And you've misspelt "address" throughout.
edited Nov 23 '18 at 22:40
answered Nov 23 '18 at 22:35
Lightness Races in OrbitLightness Races in Orbit
285k51460782
285k51460782
For the "Address" thing. I mixed up German and English. In German it is Adresse in Englisch it is address.
– TheFox
Nov 24 '18 at 8:34
add a comment |
For the "Address" thing. I mixed up German and English. In German it is Adresse in Englisch it is address.
– TheFox
Nov 24 '18 at 8:34
For the "Address" thing. I mixed up German and English. In German it is Adresse in Englisch it is address.
– TheFox
Nov 24 '18 at 8:34
For the "Address" thing. I mixed up German and English. In German it is Adresse in Englisch it is address.
– TheFox
Nov 24 '18 at 8:34
add a comment |
Perhaps, but where is the code that makes the operation? Not int he question.
– Matthieu Brucher
Nov 23 '18 at 21:28
I'm afraid you have left too many possibilities open. I recommend crafting a Minimal, Complete, and Verifiable example. If making the MCVE doesn't reveal the problem and solution to you, and it usually does, edit the question to add the MCVE.
– user4581301
Nov 23 '18 at 21:33
You are right, not enough information. So I attached the rest:
– TheFox
Nov 23 '18 at 21:36
Still missing some: specifically, the implementation of
getAddressBlocks
– Sebastian Redl
Nov 23 '18 at 21:41
@TheFox You added prose, no Minimal, Complete, and Verifiable example.
– Swordfish
Nov 23 '18 at 21:42