Fix several warnings and for now give up a bit on non copyable comparator

Author: danlark1

.travis.yml

@@ -126,7 +126,7 @@ before_install:
   - git clone https://github.com/google/googletest.git benchmark/googletest
 
 install:
-  - export CMAKE_FLAGS="-DMINISELECT_TESTING=on";
+  - export CMAKE_FLAGS="-DMINISELECT_TESTING=on -DCMAKE_BUILD_TYPE=RelWithDebInfo";
   - if [[ "${SANITIZE}" == "on" ]]; then
       export CMAKE_FLAGS="${CMAKE_FLAGS} -DMINISELECT_SANITIZE=on";
     fi

include/miniselect/pdqselect.h

@@ -501,7 +501,6 @@ template <class Iter, class Compare, bool Branchless>
 inline void pdqsort_loop(Iter begin, Iter end, Compare& comp, int bad_allowed,
                          bool leftmost = true) {
   typedef typename std::iterator_traits<Iter>::difference_type diff_t;
-  using CompType = typename median_common_detail::CompareRefType<Compare>::type;
 
   // Use a while loop for tail recursion elimination.
   while (true) {
@@ -606,7 +605,7 @@ template <class Iter, class Compare, bool Branchless>
 inline void pdqpartial_sort_loop(Iter begin, Iter mid, Iter end, Compare& comp,
                                  int bad_allowed, bool leftmost = true) {
   typedef typename std::iterator_traits<Iter>::difference_type diff_t;
-  using CompType = typename median_common_detail::CompareRefType<Compare>::type;
+
   // Use a while loop for tail recursion elimination.
   while (true) {
     diff_t size = end - begin;
@@ -714,7 +713,6 @@ template <class Iter, class Compare, bool Branchless>
 inline void pdqselect_loop(Iter begin, Iter mid, Iter end, Compare& comp,
                            int bad_allowed, bool leftmost = true) {
   typedef typename std::iterator_traits<Iter>::difference_type diff_t;
-  using CompType = typename median_common_detail::CompareRefType<Compare>::type;
 
   // Use a while loop for tail recursion elimination.
   while (true) {