Changed a few things to avoid bugs in visual studio 7.1

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403100

dlib/matrix/matrix_assign_fwd.h

@@ -31,11 +31,16 @@ namespace dlib
         struct is_small_matrix<EXP, typename enable_if_c<EXP::NR>=1 && EXP::NC>=1 &&
         EXP::NR<=17 && EXP::NC<=17 && (EXP::cost <= 70)>::type> { static const bool value = true; };
 
+        // I wouldn't use this mul object to do the multiply but visual studio 7.1 wouldn't
+        // compile otherwise.
+        template <long a, long b>
+        struct mul { const static long value = a*b; };
+
         template < typename EXP, typename enable = void >
         struct is_very_small_matrix { static const bool value = false; };
         template < typename EXP >
         struct is_very_small_matrix<EXP, typename enable_if_c<EXP::NR>=1 && EXP::NC>=1 &&
-        (EXP::NR*EXP::NC<=16) && (EXP::cost <= 70)>::type> { static const bool value = true; };
+        (mul<EXP::NR,EXP::NC>::value <= 16) && (EXP::cost <= 70)>::type> { static const bool value = true; };
 
 
         template < typename EXP, typename enable = void >

dlib/matrix/matrix_utilities.h

@@ -991,10 +991,18 @@ namespace dlib
 
 // ----------------------------------------------------------------------------------------
 
+// this is a workaround for a bug in visual studio 7.1
+    template <typename EXP>
+    struct visual_studio_sucks_cov_helper
+    {
+        typedef typename EXP::type inner_type;
+        typedef matrix<typename inner_type::type, inner_type::NR, inner_type::NR, typename EXP::mem_manager_type> type;
+    };
+
     template <
         typename EXP
         >
-    const matrix<typename EXP::type::type, EXP::type::NR, EXP::type::NR, typename EXP::mem_manager_type> covariance (
+    const typename visual_studio_sucks_cov_helper<EXP>::type covariance (
         const matrix_exp<EXP>& m
     )
     {
@@ -1026,7 +1034,7 @@ namespace dlib
 #endif
 
         // now perform the actual calculation of the covariance matrix.
-        matrix<typename EXP::type::type, EXP::type::NR, EXP::type::NR, typename EXP::mem_manager_type> cov(m(0).nr(),m(0).nr());
+        typename visual_studio_sucks_cov_helper<EXP>::type cov(m(0).nr(),m(0).nr());
         set_all_elements(cov,0);
 
         const matrix<double,EXP::type::NR,EXP::type::NC, typename EXP::mem_manager_type> avg = mean(m);