From c74c2abc4fad4e4aea83f90a7634424209df45af Mon Sep 17 00:00:00 2001
From: Kyle Lutz <kyle.r.lutz@gmail.com>
Date: Tue, 30 Dec 2014 13:44:24 -0800
Subject: [PATCH] Add four-iterator versions of equal() and mismatch()

---
 include/boost/compute/algorithm/equal.hpp    | 15 +++++++++++
 include/boost/compute/algorithm/mismatch.hpp | 19 ++++++++++++++
 test/test_equal.cpp                          | 15 +++++++++++
 test/test_mismatch.cpp                       | 26 ++++++++++++++++++++
 4 files changed, 75 insertions(+)

diff --git a/include/boost/compute/algorithm/equal.hpp b/include/boost/compute/algorithm/equal.hpp
index de63ad62..e8752062 100644
--- a/include/boost/compute/algorithm/equal.hpp
+++ b/include/boost/compute/algorithm/equal.hpp
@@ -32,6 +32,21 @@ inline bool equal(InputIterator1 first1,
                                       queue).first == last1;
 }
 
+/// \overload
+template<class InputIterator1, class InputIterator2>
+inline bool equal(InputIterator1 first1,
+                  InputIterator1 last1,
+                  InputIterator2 first2,
+                  InputIterator2 last2,
+                  command_queue &queue = system::default_queue())
+{
+    if(std::distance(first1, last1) != std::distance(first2, last2)){
+        return false;
+    }
+
+    return ::boost::compute::equal(first1, last1, first2, queue);
+}
+
 } // end compute namespace
 } // end boost namespace
 
diff --git a/include/boost/compute/algorithm/mismatch.hpp b/include/boost/compute/algorithm/mismatch.hpp
index 21cf4837..9c4a8761 100644
--- a/include/boost/compute/algorithm/mismatch.hpp
+++ b/include/boost/compute/algorithm/mismatch.hpp
@@ -64,6 +64,25 @@ mismatch(InputIterator1 first1,
     return std::make_pair(iter, first2 + std::distance(first1, iter));
 }
 
+/// \overload
+template<class InputIterator1, class InputIterator2>
+inline std::pair<InputIterator1, InputIterator2>
+mismatch(InputIterator1 first1,
+         InputIterator1 last1,
+         InputIterator2 first2,
+         InputIterator2 last2,
+         command_queue &queue = system::default_queue())
+{
+    if(std::distance(first1, last1) < std::distance(first2, last2)){
+        return ::boost::compute::mismatch(first1, last1, first2, queue);
+    }
+    else {
+        return ::boost::compute::mismatch(
+            first1, first1 + std::distance(first2, last2), first2, queue
+        );
+    }
+}
+
 } // end compute namespace
 } // end boost namespace
 
diff --git a/test/test_equal.cpp b/test/test_equal.cpp
index e86ca9d6..27299e98 100644
--- a/test/test_equal.cpp
+++ b/test/test_equal.cpp
@@ -12,6 +12,7 @@
 #include <boost/test/unit_test.hpp>
 
 #include <boost/compute/algorithm/equal.hpp>
+#include <boost/compute/algorithm/fill.hpp>
 #include <boost/compute/container/string.hpp>
 #include <boost/compute/container/vector.hpp>
 
@@ -40,4 +41,18 @@ BOOST_AUTO_TEST_CASE(equal_string)
     BOOST_CHECK(boost::compute::equal(a.begin(), a.end(), c.begin()) == false);
 }
 
+BOOST_AUTO_TEST_CASE(equal_different_range_sizes)
+{
+    boost::compute::vector<int> a(10, context);
+    boost::compute::vector<int> b(20, context);
+
+    boost::compute::fill(a.begin(), a.end(), 3, queue);
+    boost::compute::fill(b.begin(), b.end(), 3, queue);
+
+    BOOST_CHECK(boost::compute::equal(a.begin(), a.end(), b.begin(), b.end(), queue) == false);
+    BOOST_CHECK(boost::compute::equal(a.begin(), a.end(), a.begin(), a.end(), queue) == true);
+    BOOST_CHECK(boost::compute::equal(b.begin(), b.end(), a.begin(), a.end(), queue) == false);
+    BOOST_CHECK(boost::compute::equal(b.begin(), b.end(), b.begin(), b.end(), queue) == true);
+}
+
 BOOST_AUTO_TEST_SUITE_END()
diff --git a/test/test_mismatch.cpp b/test/test_mismatch.cpp
index 338afc87..70588671 100644
--- a/test/test_mismatch.cpp
+++ b/test/test_mismatch.cpp
@@ -11,6 +11,7 @@
 #define BOOST_TEST_MODULE TestMismatch
 #include <boost/test/unit_test.hpp>
 
+#include <boost/compute/algorithm/fill.hpp>
 #include <boost/compute/algorithm/mismatch.hpp>
 #include <boost/compute/container/vector.hpp>
 
@@ -34,4 +35,29 @@ BOOST_AUTO_TEST_CASE(mismatch_int)
     BOOST_CHECK_EQUAL(int(*location.second), int(7));
 }
 
+BOOST_AUTO_TEST_CASE(mismatch_different_range_sizes)
+{
+    boost::compute::vector<int> a(10, context);
+    boost::compute::vector<int> b(20, context);
+
+    boost::compute::fill(a.begin(), a.end(), 3, queue);
+    boost::compute::fill(b.begin(), b.end(), 3, queue);
+
+    typedef boost::compute::vector<int>::iterator iter;
+
+    std::pair<iter, iter> location;
+
+    location = boost::compute::mismatch(
+        a.begin(), a.end(), b.begin(), b.end(), queue
+    );
+    BOOST_CHECK(location.first == a.end());
+    BOOST_CHECK(location.second == b.begin() + 10);
+
+    location = boost::compute::mismatch(
+        b.begin(), b.end(), a.begin(), a.end(), queue
+    );
+    BOOST_CHECK(location.first == b.begin() + 10);
+    BOOST_CHECK(location.second == a.end());
+}
+
 BOOST_AUTO_TEST_SUITE_END()