From be80cefa69b314a3d9e1ab971715e84145863ebb Mon Sep 17 00:00:00 2001
From: green_machine <personal@brettmichaelgreen.com>
Date: Mon, 5 Nov 2018 18:53:20 -0500
Subject: [PATCH] support c++17

---
 src/cpp/flann/algorithms/kdtree_index.h |  5 ++++-
 src/cpp/flann/util/heap.h               |  5 ++++-
 src/cpp/flann/util/lsh_table.h          |  5 ++++-
 src/cpp/flann/util/random.h             | 21 ++++++---------------
 4 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/src/cpp/flann/algorithms/kdtree_index.h b/src/cpp/flann/algorithms/kdtree_index.h
index 1f609fbb..8185df32 100644
--- a/src/cpp/flann/algorithms/kdtree_index.h
+++ b/src/cpp/flann/algorithms/kdtree_index.h
@@ -37,6 +37,7 @@
 #include <cstring>
 #include <stdarg.h>
 #include <cmath>
+#include <random>
 
 #include "flann/general.h"
 #include "flann/algorithms/nn_index.h"
@@ -265,7 +266,9 @@ class KDTreeIndex : public NNIndex<Distance>
         /* Construct the randomized trees. */
         for (int i = 0; i < trees_; i++) {
             /* Randomize the order of vectors to allow for unbiased sampling. */
-            std::random_shuffle(ind.begin(), ind.end());
+            std::random_device rd;
+            std::mt19937 g(rd());
+            std::shuffle(ind.begin(), ind.end(), g);
             tree_roots_[i] = divideTree(&ind[0], int(size_) );
         }
         delete[] mean_;
diff --git a/src/cpp/flann/util/heap.h b/src/cpp/flann/util/heap.h
index d54a99cb..4d758807 100644
--- a/src/cpp/flann/util/heap.h
+++ b/src/cpp/flann/util/heap.h
@@ -105,8 +105,11 @@ class Heap
         count = 0;
     }
 
-    struct CompareT : public std::binary_function<T,T,bool>
+    struct CompareT
     {
+        typedef T first_argument_type;
+        typedef T second_argument_type;
+        typedef bool result_type;
         bool operator()(const T& t_1, const T& t_2) const
         {
             return t_2 < t_1;
diff --git a/src/cpp/flann/util/lsh_table.h b/src/cpp/flann/util/lsh_table.h
index d6057235..58c644ec 100644
--- a/src/cpp/flann/util/lsh_table.h
+++ b/src/cpp/flann/util/lsh_table.h
@@ -39,6 +39,7 @@
 #include <iostream>
 #include <iomanip>
 #include <limits.h>
+#include <random>
 // TODO as soon as we use C++0x, use the code in USE_UNORDERED_MAP
 #if USE_UNORDERED_MAP
 #include <unordered_map>
@@ -363,7 +364,9 @@ inline LshTable<unsigned char>::LshTable(unsigned int feature_size, unsigned int
     // A bit brutal but fast to code
     std::vector<size_t> indices(feature_size * CHAR_BIT);
     for (size_t i = 0; i < feature_size * CHAR_BIT; ++i) indices[i] = i;
-    std::random_shuffle(indices.begin(), indices.end());
+    std::random_device rd;
+    std::mt19937 g(rd());
+    std::shuffle(indices.begin(), indices.end(),g);
 
     // Generate a random set of order of subsignature_size_ bits
     for (unsigned int i = 0; i < key_size_; ++i) {
diff --git a/src/cpp/flann/util/random.h b/src/cpp/flann/util/random.h
index b7b51b43..74269b7e 100644
--- a/src/cpp/flann/util/random.h
+++ b/src/cpp/flann/util/random.h
@@ -34,6 +34,7 @@
 #include <algorithm>
 #include <cstdlib>
 #include <cstddef>
+#include <random>
 #include <vector>
 
 #include "flann/general.h"
@@ -50,9 +51,6 @@ inline void seed_random(unsigned int seed)
     srand(seed);
 }
 
-/*
- * Generates a random double value.
- */
 /**
  * Generates a random double value.
  * @param high Upper limit
@@ -61,7 +59,7 @@ inline void seed_random(unsigned int seed)
  */
 inline double rand_double(double high = 1.0, double low = 0)
 {
-    return low + ((high-low) * (std::rand() / (RAND_MAX + 1.0)));
+  return low + ((high - low) * (std::rand() / (RAND_MAX + 1.0)));
 }
 
 /**
@@ -72,17 +70,10 @@ inline double rand_double(double high = 1.0, double low = 0)
  */
 inline int rand_int(int high = RAND_MAX, int low = 0)
 {
-    return low + (int) ( double(high-low) * (std::rand() / (RAND_MAX + 1.0)));
+  return low + (int)(double(high - low) * (std::rand() / (RAND_MAX + 1.0)));
 }
 
 
-class RandomGenerator
-{
-public:
-    ptrdiff_t operator() (ptrdiff_t i) { return rand_int(i); }
-};
-
-
 /**
  * Random number generator that returns a distinct number from
  * the [0,n) interval each time.
@@ -110,14 +101,14 @@ class UniqueRandom
      */
     void init(int n)
     {
-        static RandomGenerator generator;
         // create and initialize an array of size n
         vals_.resize(n);
         size_ = n;
         for (int i = 0; i < size_; ++i) vals_[i] = i;
 
-        // shuffle the elements in the array
-        std::random_shuffle(vals_.begin(), vals_.end(), generator);
+        std::random_device rd;
+        std::mt19937 g(rd());
+        std::shuffle(vals_.begin(), vals_.end(), g);
 
         counter_ = 0;
     }