From 5e4c1080ecad84d8e1e829bcc5be035f637033d0 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Thu, 29 Jan 2015 15:39:20 +1100
Subject: [PATCH] polynomial: support eval on arbitrary types

---
 Makefile.am    |  1 +
 polynomial.cpp | 23 -----------------------
 polynomial.hpp |  8 +++++---
 polynomial.ipp | 43 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 49 insertions(+), 26 deletions(-)
 create mode 100644 polynomial.ipp

diff --git a/Makefile.am b/Makefile.am
index 56803449..b8a4166a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -118,6 +118,7 @@ UTIL_FILES   =		\
     point.ipp		\
     polynomial.cpp	\
     polynomial.hpp	\
+    polynomial.ipp	\
     pool.cpp		\
     pool.hpp		\
     pool.ipp		\
diff --git a/polynomial.cpp b/polynomial.cpp
index dc761a91..eabe3d54 100644
--- a/polynomial.cpp
+++ b/polynomial.cpp
@@ -156,26 +156,3 @@ namespace util { namespace polynomial {
         return s;
     }
 } }
-
-
-//-----------------------------------------------------------------------------
-template <size_t S>
-float
-util::polynomial::eval (const std::array<float,S> coeffs, const float x)
-{
-    float x_ = 1.f;
-    float sum = 0.f;
-    for (size_t i = 0; i < S; ++i) {
-        sum += coeffs[S-i-1] * x_;
-        x_ *= x;
-    }
-
-    return sum;
-}
-
-
-//-----------------------------------------------------------------------------
-template float util::polynomial::eval (std::array<float,1>, float);
-template float util::polynomial::eval (std::array<float,2>, float);
-template float util::polynomial::eval (std::array<float,3>, float);
-template float util::polynomial::eval (std::array<float,4>, float);
diff --git a/polynomial.hpp b/polynomial.hpp
index b7490178..2449037f 100644
--- a/polynomial.hpp
+++ b/polynomial.hpp
@@ -32,10 +32,12 @@ namespace util {
         std::array<float,S>
         solve (std::array<float,S+1>);
 
-        template <size_t S>
-        float
-        eval (std::array<float,S>, float x);
+        template <size_t S, typename T, typename U>
+        T
+        eval (std::array<T,S>, U x);
     }
 }
 
+#include "polynomial.ipp"
+
 #endif
diff --git a/polynomial.ipp b/polynomial.ipp
new file mode 100644
index 00000000..8a404d7b
--- /dev/null
+++ b/polynomial.ipp
@@ -0,0 +1,43 @@
+/*
+ * 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 2015 Danny Robson <danny@nerdcruft.net>
+ */
+
+
+#ifdef __UTIL_POLYNOMIAL_IPP
+#error "twice included ipp"
+#endif
+
+#define __UTIL_POLYNOMIAL_IPP
+
+
+//-----------------------------------------------------------------------------
+template <size_t S, typename T, typename U>
+T
+util::polynomial::eval (const std::array<T,S> coeffs, const U x)
+{
+    U x_ = 1.f;
+    T sum {0.f};
+
+    for (size_t i = 0; i < S; ++i) {
+        sum += coeffs[S-i-1] * x_;
+        x_ *= x;
+    }
+
+    return sum;
+}
+