vector: add redim operation

Makefile.am

@@ -156,6 +156,7 @@ UTIL_FILES   =		\
     types/traits.hpp	\
     vector.cpp		\
     vector.hpp		\
+    vector.ipp		\
     version.cpp		\
     version.hpp		\
     zlib.cpp		\

vector.cpp

@@ -336,6 +336,12 @@ util::vector<S,T>::is_zero (void) const {
 }
 
 
+//-----------------------------------------------------------------------------
+template <size_t S, typename T>
+const util::vector<S,T>
+util::vector<S,T>::ZERO (T{0});
+
+
 //-----------------------------------------------------------------------------
 template <size_t S, typename T>
 void

vector.hpp

@@ -75,6 +75,9 @@ namespace util {
         vector<S,T>  normalised [[gnu::warn_unused_result]] (void) const;
 
         template <size_t D> vector<D,T> redim (void) const;
+        template <size_t D> vector<D,T> redim (const util::vector<D,T> &fill) const;
+
+        static const vector<S,T> ZERO;
 
         void sanity (void) const;
     };
@@ -106,6 +109,7 @@ namespace util {
     typedef vector<3,double> vector4d;
 }
 
+#include "vector.ipp"
 
 #endif
 

vector.ipp

@@ -0,0 +1,59 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ * 
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2014 Danny Robson <danny@nerdcruft.net>
+ */
+
+#ifdef __UTIL_VECTOR_IPP
+#error "twice included ipp"
+#endif
+
+#define __UTIL_VECTOR_IPP
+
+#include "maths.hpp"
+
+namespace util {
+    //-------------------------------------------------------------------------
+    template<size_t S, typename T>
+    template<size_t D>
+    vector<D,T> vector<S,T>::redim (void) const {
+        vector<D,T> out;
+        std::copy_n (std::begin (this->data),
+                     min (S, D),
+                     std::begin (out.data));
+        return out;
+    }
+
+
+    //-------------------------------------------------------------------------
+    template<size_t S, typename T>
+    template<size_t D>
+    vector<D,T> vector<S,T>::redim (const vector<D,T> &fill) const {
+        vector<D,T> out;
+
+        static constexpr auto L1 = min (S, D);
+        static constexpr auto L2 = D - L1;
+
+        std::copy_n (std::begin (this->data),
+                     L1,
+                     std::begin (out.data));
+
+        std::copy_n (fill.data + L1,
+                     L2,
+                     out.data + L1);
+        return out;
+    }
+}