From 17f9326ecc7b5b94e8b50d480c51971abc08b5a7 Mon Sep 17 00:00:00 2001
From: CromwellEnage <32967088+CromwellEnage@users.noreply.github.com>
Date: Wed, 19 Sep 2018 12:06:36 -0400
Subject: [PATCH] index_range.size() was missing

Added missing size() member function to index_range in accordance with reference documentation.
---
 include/boost/multi_array/index_range.hpp | 9 +++++++++
 test/range1.cpp                           | 9 +++++++++
 2 files changed, 18 insertions(+)

diff --git a/include/boost/multi_array/index_range.hpp b/include/boost/multi_array/index_range.hpp
index 3d6035e7..b0896a0f 100644
--- a/include/boost/multi_array/index_range.hpp
+++ b/include/boost/multi_array/index_range.hpp
@@ -107,6 +107,15 @@ namespace multi_array {
 
     index stride() const { return stride_; }
 
+    size_type size(index idx) const
+    {
+      return (
+        (this->start_ == this_type::from_start()) || (
+          this->finish_ == this_type::to_end()
+        )
+      ) ? idx : ((this->finish_ - this->start_) / this->stride_);
+    }
+
     void set_index_range(index start, index finish, index stride=1)
     {
       start_ = start;
diff --git a/test/range1.cpp b/test/range1.cpp
index a673a9b3..db9fef88 100644
--- a/test/range1.cpp
+++ b/test/range1.cpp
@@ -33,6 +33,7 @@ test_main(int,char*[])
     BOOST_CHECK(r1.start() == -3);
     BOOST_CHECK(r1.finish() == 5);
     BOOST_CHECK(r1.stride() == 1);
+    BOOST_CHECK(r1.size(0) == 8);
     BOOST_CHECK(!r1.is_degenerate());
     BOOST_CHECK(r1.get_start(0) == -3);
     BOOST_CHECK(r1.get_finish(100) == 5);
@@ -43,6 +44,7 @@ test_main(int,char*[])
     BOOST_CHECK(r2.start() == -3);
     BOOST_CHECK(r2.finish() == 5);
     BOOST_CHECK(r2.stride() == 2);
+    BOOST_CHECK(r2.size(0) == 4);
     BOOST_CHECK(!r2.is_degenerate());
   }
 
@@ -52,6 +54,7 @@ test_main(int,char*[])
     BOOST_CHECK(r3.start() == 5);
     BOOST_CHECK(r3.finish() == 6);
     BOOST_CHECK(r3.stride() == 1);
+    BOOST_CHECK(r3.size(0) == 1);
     BOOST_CHECK(r3.is_degenerate());
   }
 
@@ -61,6 +64,7 @@ test_main(int,char*[])
     BOOST_CHECK(r4.get_start(0) == 0);
     BOOST_CHECK(r4.get_finish(100) == 100);
     BOOST_CHECK(r4.stride() == 1);
+    BOOST_CHECK(r4.size(0) == 0);
   }
 
   {
@@ -69,6 +73,7 @@ test_main(int,char*[])
     BOOST_CHECK(r5.start() == -3);
     BOOST_CHECK(r5.stride() == 2);
     BOOST_CHECK(r5.finish() == 7);
+    BOOST_CHECK(r5.size(0) == 5);
   }
 
   // try out all the comparison operators
@@ -77,6 +82,7 @@ test_main(int,char*[])
     BOOST_CHECK(r6.start() == -3);
     BOOST_CHECK(r6.stride() == 2);
     BOOST_CHECK(r6.finish() == 7);
+    BOOST_CHECK(r6.size(0) == 5);
   }
 
   {
@@ -84,6 +90,7 @@ test_main(int,char*[])
     BOOST_CHECK(r7.start() == -2);
     BOOST_CHECK(r7.stride() == 1);
     BOOST_CHECK(r7.finish() == 8);
+    BOOST_CHECK(r7.size(0) == 10);
   }
 
   // arithmetic operators
@@ -92,6 +99,7 @@ test_main(int,char*[])
     BOOST_CHECK(r8.start() == 2);
     BOOST_CHECK(r8.stride() == 1);
     BOOST_CHECK(r8.finish() == 7);
+    BOOST_CHECK(r8.size(0) == 5);
   }
 
   {
@@ -99,6 +107,7 @@ test_main(int,char*[])
     BOOST_CHECK(r9.start() == -2);
     BOOST_CHECK(r9.stride() == 1);
     BOOST_CHECK(r9.finish() == 3);
+    BOOST_CHECK(r9.size(0) == 5);
   }
 
   return boost::exit_success;