Issue with the templatized version of insertion sort - sorting

Question

Below is the templatized version of insertion sort which results in compilation errors to perform insertion sort in place without any extra space.
#include <vector>
#include <iostream>
#include <algorithm>
#include <iterator>
using namespace std;
template <typename T>
insertSort(T start, T end)
{
typename std::vector<typename std::iterator_traits<T>::value_type> TmpVec;
TmpVec tmp(std::make_move_iterator(start), std::make_move_iterator(end));
TmpVec::iterator begin = std::begin(tmp);
TmpVec::iterator end = std::end(tmp);
for(TmpVec::iterator i = begin; i != end; i++)
{
typename std::iterator_traits<T>::value_type value = *i;
TmpVec::iterator pos = i;
while (pos > start && *(pos-1) > value)
{
*pos = std::move(*(pos-1));
--pos;
}
*pos = value;
}
}
int main(int argc, char** argv) {
std::vector<double> arr = {1,5,3,2,6,3,9,8};
insertSort<double>(arr.begin(), arr.end());
for(int i=0; i<arr.size(); i++)
{
std::cout << arr[i] << " ";
}
return 0;
}
I am compiling this with the following compilation line.
g++ -std=c++11 -c -g -MMD -MP -MF "build/Debug/MinGW-Windows/main.o.d" -o build/Debug/MinGW-Windows/main.o main.cpp
This yields the following errors.
main.cpp: In function 'int insertSort(T, T)':
main.cpp:21:12: error: expected ';' before 'tmp'
TmpVec tmp(std::make_move_iterator(start), std::make_move_iterator(end));
^
main.cpp:22:5: error: 'TmpVec' is not a class, namespace, or enumeration
TmpVec::iterator begin = std::begin(tmp);
^
main.cpp:23:5: error: 'TmpVec' is not a class, namespace, or enumeration
TmpVec::iterator end = std::end(tmp);
^
main.cpp:24:9: error: 'TmpVec' is not a class, namespace, or enumeration
for(TmpVec::iterator i = begin; i != end; i++)
^
main.cpp:24:37: error: 'i' was not declared in this scope
for(TmpVec::iterator i = begin; i != end; i++)
^
main.cpp:27:9: error: 'TmpVec' is not a class, namespace, or enumeration
TmpVec::iterator pos = i;
^
main.cpp:28:16: error: 'pos' was not declared in this scope
while (pos > start && *(pos-1) > value)
^
main.cpp:33:10: error: 'pos' was not declared in this scope
*pos = value;
^
main.cpp: In function 'int main(int, char**)':
main.cpp:40:46: error: no matching function for call to 'insertSort(std::vector<double>::iterator, std::vector<double>::iterator)'
insertSort<double>(arr.begin(), arr.end());
^
main.cpp:40:46: note: candidate is:
main.cpp:18:1: note: template<class T> int insertSort(T, T)
insertSort(T start, T end)
^
main.cpp:18:1: note: template argument deduction/substitution failed:
main.cpp:40:46: note: cannot convert 'arr.std::vector<_Tp, _Alloc>::begin<double, std::allocator<double> >()' (type 'std::vector<double>::iterator {aka __gnu_cxx::__normal_iterator<double*, std::vector<double> >}') to type 'double'
insertSort<double>(arr.begin(), arr.end());
Kindly help in solving the above issue.

Answer 1

typename std::vector<typename std::iterator_traits<T>::value_type> TmpVec;
this states std::vector<typename std::iterator_traits<T>::value_type> is a typename. A compiler should issue a warning/error, because the typename is redundant.
It then declares a variable TmpVec of that type.
Every use after that uses TmpVec as if it was a type, not a variable.
You probably want
typedef std::vector<typename std::iterator_traits<T>::value_type> TmpVec;
I'd also advise
using tmp_iterator = typename TmpVec::iterator;
and using tmp_iterator as a type instead of TmpVec::iterator.