Help with std::map

[Xuan Liu]

Hi, everyone. I need your help... I wanted to fill an std::map with some value_type arguments. When I run my code, the following error occured. Can anyone tell me how to fix it? Thanks!

error C2664: 'std::pair<_Ty1,_Ty2>::pair(const unsigned int &,const _Ty2 &)' : cannot convert parameter 2 from 'std::pair<_Ty1,_Ty2>' to 'const

typedef boost::numeric::ublas::vector<double> BVector;
typedef std::map<unsigned int,std::pair<unsigned int, std::vector<BVector>>> MyMap;

using namespace std;
using boost::numeric::ublas::zero_vector;

unsigned int iMaxLevel(1000);
vector<BVector> mean_var(iMaxLevel,zero_vector<double>(2)); 
vector<unsigned int> vn(iMaxLevel);
MyMap mapRes;
for(unsigned int i=0; i<iMaxLevel; ++i)
   mapRes.emplace(i,make_pair(vn[i],mean_var[i])); // error urcurs in this line 

[Peter87]

make_pair(vn[i],mean_var[i]) gives you a std::pair<unsigned int, BVector>.
The value type of MyMap is std::pair<unsigned int, std::vector<BVector>>.
See the difference?

[Xuan Liu]

why? I used the map::emplace() function...

mapRes.emplace(i,make_pair(vn[i],mean_var[i]));

[Peter87]

Maybe you got the MyMap typedef wrong. Should it be

typedef std::map<unsigned int,std::pair<unsigned int, BVector>> MyMap;

?

[Xuan Liu]

The type definition of MyMap is what I want. It is a vector of BVectors. For example, mean_var is a vector containing the statistics of mean_var.size() sets of samples.
I've been stuck with this problem for 6 hours...

[Peter87]

Do you want all map elements to contain all the sets of samples? In that case you should remove the second [i] from line 12.

mapRes.emplace(i,make_pair(vn[i],mean_var));

Is this really what you want?

[Peter87]

Maybe there is some confusion here:

Xuan Liu wrote:

The type definition of MyMap is what I want. It is a vector of BVectors. For example, mean_var is a vector ...

MyMap is not a vector. It is a map.

It is true what you say about mean_var but MyMap is something else.

[Xuan Liu]

Yes, you're right. Thank you!!!