[Boost-gil] Fwd: [boost] please integrate patches for Boost.Gil and Boost.Graph

Subject: [Boost-gil] Fwd: [boost] please integrate patches for Boost.Gil and Boost.Graph
From: Mateusz Loskot (mateusz_at_[hidden])
Date: 2018-04-09 15:11:09

This request below posted to Boost dev ML may be of interest here

ML

---------- Forwarded message ----------
From: Brook Milligan via Boost <boost_at_[hidden]>
Date: 9 April 2018 at 17:07
Subject: [boost] please integrate patches for Boost.Gil and Boost.Graph
To: boost_at_[hidden]
Cc: Brook Milligan <brook_at_[hidden]>

I am not sure what the correct procedure for this is, but there are at
least two old patches that would improve Boost.Gil and Boost.Graph.  I
would greatly appreciate it if someone integrates these.  I have been
using these for some time now with no detrimental effects.

The patch to Boost.Gil corrects clearly incorrect code.

The patch to Boost.Graph solves a problem that should never have been
in the original design in the first place.  Since it expands the
acceptable set of arguments to cover the full range of values any user
would expect and has the original semantics for cases that worked
before, as far as I can see there can be no effect on existing user
code.

Thank you very much.

Cheers,
Brook

See the following:

- https://lists.boost.org/Archives/boost/2013/02/200721.php
- https://svn.boost.org/trac10/ticket/7270
- https://svn.boost.org/trac10/ticket/9517
- https://svn.boost.org/trac10/attachment/ticket/9517/gil_channel_algorithm.patch
- https://svn.boost.org/trac10/ticket/13397

--- boost/gil/channel_algorithm.hpp.orig        2018-02-23
22:45:42.000000000 -0700
+++ boost/gil/channel_algorithm.hpp     2018-03-11 22:05:31.000000000 -0600
@@ -25,6 +25,7 @@

 #include "gil_config.hpp"
 #include "channel.hpp"
+#include <limits>
 #include <boost/mpl/less.hpp>
 #include <boost/mpl/integral_c.hpp>
 #include <boost/mpl/greater.hpp>
@@ -51,7 +52,7 @@

 template <typename UnsignedIntegralChannel>
-struct unsigned_integral_max_value : public
mpl::integral_c<UnsignedIntegralChannel,-1> {};
+struct unsigned_integral_max_value : public
mpl::integral_c<UnsignedIntegralChannel,std::numeric_limits<UnsignedIntegralChannel>::max()>
{};

 template <>
 struct unsigned_integral_max_value<uint8_t> : public
mpl::integral_c<uint32_t,0xFF> {};

Allow dimensions to have length >= 1, rather than > 1.
See https://svn.boost.org/trac10/ticket/11735.

--- boost/graph/grid_graph.hpp.orig     2017-12-13 16:56:43.000000000 -0700
+++ boost/graph/grid_graph.hpp  2018-04-07 09:33:56.000000000 -0600
@@ -630,15 +630,17 @@

         // If the vertex is on the edge of this dimension, then its
         // number of out edges is dependent upon whether the dimension
-        // wraps or not.
-        if ((vertex[dimension_index] == 0) ||
-            (vertex[dimension_index] == (length(dimension_index) - 1))) {
-          out_edge_count += (wrapped(dimension_index) ? 2 : 1);
-        }
-        else {
-          // Next and previous edges, regardless or wrapping
-          out_edge_count += 2;
-        }
+        // wraps or not, but only if the length is > 1.
+       if (length(dimension_index) > 1) {
+          if ((vertex[dimension_index] == 0) ||
+              (vertex[dimension_index] == (length(dimension_index) - 1))) {
+            out_edge_count += (wrapped(dimension_index) ? 2 : 1);
+          }
+          else {
+            // Next and previous edges, regardless or wrapping
+            out_edge_count += 2;
+          }
+       }
       }

       return (out_edge_count);

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-- 
Mateusz Loskot, http://mateusz.loskot.net