C++ - std::map.insert() segmentation fault - c++

Question

I get a segmentation fault when i try to insert into my map.
The function looks something like this:
void add(std::string id, std::string name)
{
Asset asset(nullptr, false, name);
mAssets.insert(std::make_pair<std::string, Asset>(id,asset)); <-- This line gives segfault
}
mAssets is simply declared
std::map<assetID, Asset> mAssets;
And the Asset class is (sloppy) declared like this:
class Asset
{
public:
Asset(T* a, bool l, std::string f) : asset(a), loaded(l), filename(f)
{
}
Asset(const Asset& copy)
{
loaded = copy.loaded;
filename = copy.filename;
asset = new T();
*asset = *copy.asset;
}
~Asset()
{
delete asset;
}
Asset& operator=(const Asset& other)
{
Asset temp(other);
loaded = temp.loaded;
filename = temp.filename;
std::swap(asset,temp.asset);
return *this;
}
T* asset;
bool loaded;
std::string filename;
};

Answer 1

Your problem is here in your copy constructor:
asset = new T();
*asset = *copy.asset;
I will leave it to you to work out why...

Answer 2

On your copy constructor you are derefferencing a null pointer:
*asset = *copy.asset
from
Asset asset(nullptr, false, name);
Verify your pointers asigments and avoid dereferencing null pointers:
Asset(const Asset& copy)
{
loaded = copy.loaded;
filename = copy.filename;
if (copy.asset)
{
asset = new T(); // better may be asset = new T(copy)
*asset = *copy.asset;
}
else
{
asset = nullptr
}
}

Answer 3

*asset = *copy.asset; //you should check whether asset is NULL or not then check for asset
This is how your code will work:
#include <iostream>
#include <map>
using namespace std;
template<class T>
class Asset
{
public:
Asset(T* a, bool l, std::string f) : asset(a), loaded(l), filename(f)
{
}
Asset(const Asset& copy)
{
cout<<"copy"<<endl;
loaded = copy.loaded;
filename = copy.filename;
asset = new T();
if(&copy != NULL)
{
if(copy.asset != NULL)
*asset = *(copy.asset);
}
}
~Asset()
{
delete asset;
}
Asset& operator=(const Asset& other)
{
Asset temp(other);
loaded = temp.loaded;
filename = temp.filename;
std::swap(asset,temp.asset);
return *this;
}
T* asset;
bool loaded;
std::string filename;
};
std::map <string,Asset<int> > mAssets;
void add(std::string id, std::string name)
{
Asset<int> asset(NULL, false, name);
mAssets.insert(std::make_pair<std::string, Asset<int> >(id,asset)); //<-- This line gives segfault
}
int main()
{
add("1","hi");
cout<<"run"<<endl;
}