Mark Eigen2 support deprecated

Eigen/Eigen2Support

@@ -14,12 +14,25 @@
 #error Eigen2 support must be enabled by defining EIGEN2_SUPPORT before including any Eigen header
 #endif
 
+#ifndef EIGEN_NO_EIGEN2_DEPRECATED_WARNING
+
+#if defined(__GNUC__) || defined(__INTEL_COMPILER) || defined(__clang__)
+#warning "Eigen2 support is deprecated in Eigen 3.2.x and it will be removed in Eigen 3.3. (Define EIGEN_NO_EIGEN2_DEPRECATED_WARNING to disable this warning)"
+#else
+#pragma message ("Eigen2 support is deprecated in Eigen 3.2.x and it will be removed in Eigen 3.3. (Define EIGEN_NO_EIGEN2_DEPRECATED_WARNING to disable this warning)")
+#endif
+
+#endif // EIGEN_NO_EIGEN2_DEPRECATED_WARNING
+
 #include "src/Core/util/DisableStupidWarnings.h"
 
 /** \ingroup Support_modules
   * \defgroup Eigen2Support_Module Eigen2 support module
-  * This module provides a couple of deprecated functions improving the compatibility with Eigen2.
   *
+  * \warning Eigen2 support is deprecated in Eigen 3.2.x and it will be removed in Eigen 3.3.
+  *
+  * This module provides a couple of deprecated functions improving the compatibility with Eigen2.
+  * 
   * To use it, define EIGEN2_SUPPORT before including any Eigen header
   * \code
   * #define EIGEN2_SUPPORT

doc/A05_PortingFrom2To3.dox

@@ -2,6 +2,8 @@ namespace Eigen {
 
 /** \page Eigen2ToEigen3 Porting from Eigen2 to Eigen3
 
+<div class="bigwarning">Eigen2 support is deprecated in Eigen 3.2.x and it will be removed in Eigen 3.3.</div>
+
 This page lists the most important API changes between Eigen2 and Eigen3,
 and gives tips to help porting your application from Eigen2 to Eigen3.
 

doc/A10_Eigen2SupportModes.dox

@@ -2,6 +2,8 @@ namespace Eigen {
 
 /** \page Eigen2SupportModes Eigen 2 support modes
 
+<div class="bigwarning">Eigen2 support is deprecated in Eigen 3.2.x and it will be removed in Eigen 3.3.</div>
+
 This page documents the Eigen2 support modes, a powerful tool to help migrating your project from Eigen 2 to Eigen 3.
 Don't miss our page on \ref Eigen2ToEigen3 "API changes" between Eigen 2 and Eigen 3.
 

doc/eigendoxy.css

@@ -199,3 +199,13 @@ h3.version {
 td.width20em p.endtd {
   width:  20em;
 }
+
+.bigwarning {
+  font-size:2em;
+  font-weight:bold;
+  margin:1em;
+  padding:1em;
+  color:red;
+  border:solid;
+}
+