Fix linux build.

include/tesseract/genericvector.h

@@ -37,9 +37,20 @@ namespace tesseract {
 // sort that works.
 template <typename T>
 class GenericVector : public std::vector<T> {
+  using base = std::vector<T>;
  public:
   using std::vector<T>::vector;
 
+  using base::begin;
+  using base::end;
+  using base::data;
+  using base::capacity;
+  using base::reserve;
+  using base::resize;
+  using base::back;
+  using base::clear;
+  using base::push_back;
+
   GenericVector<T>& operator+=(const GenericVector& other);
 
   // Double the size of the internal array.
@@ -61,7 +72,7 @@ class GenericVector : public std::vector<T> {
   }
 
   int size() const {
-      return vector::size();
+      return base::size();
   }
 
   // Return the object from an index.
@@ -442,7 +453,7 @@ class PointerVector : public GenericVector<T*> {
         delete GenericVector<T*>::data()[old_index];
       }
     }
-    resize(new_size);
+    GenericVector<T*>::resize(new_size);
   }
 
   // Clear the array, calling the clear callback function if any.
@@ -650,7 +661,7 @@ const T& GenericVector<T>::get(int index) const {
 template <typename T>
 T GenericVector<T>::pop_back() {
   auto b = back();
-  vector::pop_back();
+  base::pop_back();
   return b;
 }
 
@@ -666,7 +677,7 @@ void GenericVector<T>::set(const T& t, int index) {
 // at the specified index.
 template <typename T>
 void GenericVector<T>::insert(const T& t, int index) {
-  vector::insert(begin() + index, t);
+  base::insert(begin() + index, t);
 }
 
 // Removes an element at the given index and

src/api/baseapi.cpp

@@ -129,7 +129,9 @@ const int kMaxIntSize = 22;
 static void addAvailableLanguages(const STRING &datadir, const STRING &base,
                                   GenericVector<STRING>* langs)
 {
-  const STRING base2 = (base.c_str()[0] == '\0') ? base : base + "/";
+  auto base2 = base;
+  if (!base2.empty())
+    base2 += "/";
   const size_t extlen = sizeof(kTrainedDataSuffix);
 #ifdef _WIN32
     WIN32_FIND_DATA data;

src/ccutil/kdpair.h

@@ -34,9 +34,14 @@ namespace tesseract {
 // A useful base struct to facilitate the common operation of sorting a vector
 // of simple or smart-pointer data using a separate key. Similar to STL pair.
 template <typename Key, typename Data>
-struct KDPair : public std::pair<Key, Data> {
+class KDPair : public std::pair<Key, Data> {
+  using base = std::pair<Key, Data>;
+ public:
   using std::pair<Key, Data>::pair;
 
+  using base::first;
+  using base::second;
+
   int operator==(const KDPair<Key, Data>& other) const {
     return first == other.first;
   }
@@ -58,7 +63,8 @@ struct KDPair : public std::pair<Key, Data> {
 // Specialization of KDPair to provide operator< for sorting in increasing order
 // and recasting of data pointers for use with DoublePtr.
 template <typename Key, typename Data>
-struct KDPairInc : public KDPair<Key, Data> {
+class KDPairInc : public KDPair<Key, Data> {
+ public:
   using KDPair<Key, Data>::KDPair;
 
   // Operator< facilitates sorting in increasing order.
@@ -70,7 +76,8 @@ struct KDPairInc : public KDPair<Key, Data> {
 // Specialization of KDPair to provide operator< for sorting in decreasing order
 // and recasting of data pointers for use with DoublePtr.
 template <typename Key, typename Data>
-struct KDPairDec : public KDPair<Key, Data> {
+class KDPairDec : public KDPair<Key, Data> {
+ public:
   using KDPair<Key, Data>::KDPair;
 
   // Operator< facilitates sorting in decreasing order by using operator> on
@@ -87,14 +94,18 @@ struct KDPairDec : public KDPair<Key, Data> {
 // only a single instance of KDPtrPair holds a specific data pointer.
 template <typename Key, typename Data>
 class KDPtrPair : public std::pair<Key, std::unique_ptr<Data>> {
+  using base = std::pair<Key, std::unique_ptr<Data>>;
  public:
+  using base::first;
+  using base::second;
+
   KDPtrPair() = default;
   KDPtrPair(Key k, Data* d) : std::pair<Key, std::unique_ptr<Data>>(k, d) {}
   KDPtrPair(KDPtrPair &&src) = default;
   KDPtrPair &operator=(KDPtrPair &&src) = default;
 
   int operator==(const KDPtrPair<Key, Data>& other) const {
-    return key_ == other.key_;
+    return key() == other.key();
   }
 
   // Accessors.