version_number_t: provide all comparison operators via Boost::Operators

NEWS.md

@@ -16,6 +16,10 @@
   v36.0.0. If it does, it will be updated to the built-in list changed in
   v37.0.0. Fixes #2611.
 
+## Build system changes
+
+* Boost's Operators header library is now required.
+
 
 # Version 37.0.0 "Leave It" 2019-08-24
 

README.md

@@ -94,8 +94,8 @@ programs and libraries you absolutely need are:
 - [zlib](http://www.zlib.net/) — a compression library
 
 - [Boost](http://www.boost.org/) — Several of Boost's libraries are
-  used: `RegEx`, `filesystem`, `system`, `math`, `Range`, `rational`,
-  `variant`. At least v1.49.0 is required.
+  used: `RegEx`, `filesystem`, `system`, `math`, `operators`, `Range`,
+  `rational`, `variant`. At least v1.49.0 is required.
 
 - [libxslt's xsltproc binary](http://xmlsoft.org/libxslt/) and
   [DocBook XSL stylesheets](https://sourceforge.net/projects/docbook/files/docbook-xsl/)

ac/boost.m4

@@ -48,6 +48,10 @@ if test x"$ac_cv_header_boost_integer_common_factor_hpp" != xyes; then
   ])
 fi
 
+AX_BOOST_CHECK_HEADERS([boost/operators.hpp],,[
+  AC_MSG_ERROR([Boost's Operators library is required but wasn't found])
+])
+
 AX_BOOST_CHECK_HEADERS([boost/range.hpp],,[
   AC_MSG_ERROR([Boost's Range library is required but wasn't found])
 ])

src/common/version.cpp

@@ -102,6 +102,13 @@ version_number_t::operator <(const version_number_t &cmp)
   return compare(cmp) == -1;
 }
 
+bool
+version_number_t::operator ==(const version_number_t &cmp)
+  const
+{
+  return compare(cmp) == 0;
+}
+
 std::string
 version_number_t::to_string()
   const

src/common/version.h

@@ -16,6 +16,7 @@
 #include "common/common_pch.h"
 
 #include <boost/date_time/posix_time/posix_time.hpp>
+#include <boost/operators.hpp>
 
 #include "common/xml/xml.h"
 
@@ -24,7 +25,7 @@
 #define MTX_DOWNLOAD_URL      "https://mkvtoolnix.download/downloads.html"
 #define MTX_NEWS_URL          "https://mkvtoolnix.download/doc/NEWS.md"
 
-struct version_number_t {
+struct version_number_t: boost::totally_ordered<version_number_t> {
   std::vector<unsigned int> parts;
   unsigned int build{};
   bool valid{};
@@ -33,6 +34,7 @@ struct version_number_t {
   version_number_t(const std::string &s);
 
   bool operator <(const version_number_t &cmp) const;
+  bool operator ==(const version_number_t &cmp) const;
   int compare(const version_number_t &cmp) const;
 
   std::string to_string() const;