c++ - istringstream from getline return double for last element in line -

i have file number of chars separated spaces:

# cat file.txt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

i trying put them structure, example vector, using ifstream , istringstream in followed way:

string line; ifstream file("file.txt"); vector<char> row  while(getline(file, line)){     char a;      istringstream iss(line);     vector<char> row;     while(iss){         iss >> a;         row.push_back(a);     }     table.pushback(row); } 

the issue iss return me last element twice in configuration:

for(int i=0; i<table.size(); i++) {     for(int j=0; j<table[i].size(); j++){         cout << table[i][j] << " ";     }     cout <<endl; }  . . . . . . . . . . .  . . . . . . . . . . .  . . . . . . . . . . .  . . . . . . . . . . .  . . . . . . . . . . .  .  

i believe issue caused end of line character, , reasons, last char stored.

also when read numbers line "1 2 3 4 5 6 7" program print "1 2 3 4 5 6 7 7"

is particular reason why way of processing file somehow wrong? or maybe missing trivial in example.

statement while(iss) calls bool-operator on istringstream, indicates if failure has occurred in previous read. hence, when last read has been successful, loop entered once more (because no failure has happened far); next read of iss >> a fail, since ignore return value of operation iss >> a, (unchanged) value of a pushed once more vector.

write while(iss >> a) instead.