+++ /dev/null
-/* -*- C++ -*- ------------------------------------------------------------
-
-Copyright (c) 2007 Jesse Anders and Demian Nave http://cmldev.net/
-
-The Configurable Math Library (CML) is distributed under the terms of the
-Boost Software License, v1.0 (see cml/LICENSE for details).
-
- *-----------------------------------------------------------------------*/
-/** @file
- * @brief
- */
-
-#ifndef scalar_promotions_h
-#define scalar_promotions_h
-
-#include <complex>
-#include <cml/core/cml_meta.h>
-
-namespace cml {
-namespace et {
-
-/* The type promotion code below is a slightly modified version of:
- * http://ubiety.uwaterloo.ca/~tveldhui/papers/techniques/techniques01.html
- */
-namespace detail {
-
-template<class T>
-struct precision_trait {
- enum { precisionRank = 0,
- knowPrecisionRank = 0 };
-};
-
-#define DECLARE_PRECISION(T,rank) \
- template<> \
- struct precision_trait< T > { \
- enum { precisionRank = rank, \
- knowPrecisionRank = 1 }; \
- };
-
-DECLARE_PRECISION(int,100)
-DECLARE_PRECISION(unsigned int,200)
-DECLARE_PRECISION(long,300)
-DECLARE_PRECISION(unsigned long,400)
-
-DECLARE_PRECISION(long long,425)
-DECLARE_PRECISION(unsigned long long,475)
-
-DECLARE_PRECISION(float,500)
-DECLARE_PRECISION(double,600)
-DECLARE_PRECISION(long double,700)
-DECLARE_PRECISION(std::complex<float>,800)
-DECLARE_PRECISION(std::complex<double>,900)
-DECLARE_PRECISION(std::complex<long double>,1000)
-
-template<class T>
-struct autopromote_trait {
- typedef T T_numtype;
-};
-
-#define DECLARE_AUTOPROMOTE(T1,T2) \
- template<> \
- struct autopromote_trait<T1> { \
- typedef T2 T_numtype; \
- };
-
-// These are the odd cases where small integer types
-// are automatically promoted to int or unsigned int for
-// arithmetic.
-DECLARE_AUTOPROMOTE(bool, int)
-DECLARE_AUTOPROMOTE(char, int)
-DECLARE_AUTOPROMOTE(unsigned char, int)
-DECLARE_AUTOPROMOTE(short int, int)
-DECLARE_AUTOPROMOTE(short unsigned int, unsigned int)
-
-template<class T1, class T2, int promoteToT1>
-struct promote2 {
- typedef T1 T_promote;
-};
-
-template<class T1, class T2>
-struct promote2<T1,T2,0> {
- typedef T2 T_promote;
-};
-
-template<class T1_orig, class T2_orig>
-struct promote_trait {
-
- // Need to remove const-ness:
- typedef typename cml::remove_const<T1_orig>::type T1_non_const;
- typedef typename cml::remove_const<T2_orig>::type T2_non_const;
-
- // Handle promotion of small integers to int/unsigned int
- typedef typename autopromote_trait<T1_non_const>::T_numtype T1;
- typedef typename autopromote_trait<T2_non_const>::T_numtype T2;
-
- // True if T1 is higher ranked
- enum {
- T1IsBetter =
- (int) precision_trait<T1>::precisionRank >
- (int) precision_trait<T2>::precisionRank,
-
- // True if we know ranks for both T1 and T2
- knowBothRanks =
- precision_trait<T1>::knowPrecisionRank
- && precision_trait<T2>::knowPrecisionRank,
-
- // True if we know T1 but not T2
- knowT1butNotT2 = precision_trait<T1>::knowPrecisionRank
- && !(precision_trait<T2>::knowPrecisionRank),
-
- // True if we know T2 but not T1
- knowT2butNotT1 = precision_trait<T2>::knowPrecisionRank
- && !(precision_trait<T1>::knowPrecisionRank),
-
- // True if T1 is bigger than T2
- T1IsLarger = sizeof(T1) >= sizeof(T2),
-
- // We know T1 but not T2: true
- // We know T2 but not T1: false
- // Otherwise, if T1 is bigger than T2: true
- defaultPromotion = knowT1butNotT2 ? false :
- (knowT2butNotT1 ? true : T1IsLarger)
- };
-
- // If we have both ranks, then use them.
- // If we have only one rank, then use the unknown type.
- // If we have neither rank, then promote to the larger type.
-
- enum {
- promoteToT1 = (knowBothRanks ? T1IsBetter : defaultPromotion)
- ? 1 : 0
- };
-
- typedef typename promote2<T1,T2,promoteToT1>::T_promote T_promote;
-};
-
-} // namespace detail
-
-/** Defers to detail::promote_trait<>. */
-template<class E1, class E2> struct ScalarPromote
-{
- typedef typename detail::promote_trait<E1,E2>::T_promote type;
-};
-
-} // namespace et
-} // namespace cml
-
-#endif
-
-// -------------------------------------------------------------------------
-// vim:ft=cpp