1 /*
  2  *   Copyright (c) 2010, Michael Lehn
  3  *
  4  *   All rights reserved.
  5  *
  6  *   Redistribution and use in source and binary forms, with or without
  7  *   modification, are permitted provided that the following conditions
  8  *   are met:
  9  *
 10  *   1) Redistributions of source code must retain the above copyright
 11  *      notice, this list of conditions and the following disclaimer.
 12  *   2) Redistributions in binary form must reproduce the above copyright
 13  *      notice, this list of conditions and the following disclaimer in
 14  *      the documentation and/or other materials provided with the
 15  *      distribution.
 16  *   3) Neither the name of the FLENS development group nor the names of
 17  *      its contributors may be used to endorse or promote products derived
 18  *      from this software without specific prior written permission.
 19  *
 20  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 21  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 22  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 23  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 24  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 25  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 26  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 27  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 28  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 29  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 30  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 31  */
 32 
 33 #ifndef FLENS_AUX_PROMOTION_H
 34 #define FLENS_AUX_PROMOTION_H 1
 35 
 36 #include <flens/aux/ifelseif.h>
 37 #include <flens/aux/isconvertible.h>
 38 
 39 namespace flens {
 40 
 41 template <typename A, typename B>
 42 struct Promotion
 43 {
 44     typedef typename IfElseIf<sizeof(B)<=sizeof(A), A,
 45                               sizeof(A)<=sizeof(B), B>::Type     Type;
 46 };
 47 
 48 template <typename A>
 49 struct Promotion<A, A>
 50 {
 51     typedef A  Type;
 52 };
 53 
 54 //-- int, float ----------------------------------------------------------------
 55 template <>
 56 struct Promotion<intfloat>
 57 {
 58     typedef float  Type;
 59 };
 60 
 61 template <>
 62 struct Promotion<floatint>
 63 {
 64     typedef float  Type;
 65 };
 66 
 67 //-- long, float ----------------------------------------------------------------
 68 template <>
 69 struct Promotion<longfloat>
 70 {
 71     typedef float  Type;
 72 };
 73 
 74 template <>
 75 struct Promotion<floatlong>
 76 {
 77     typedef float  Type;
 78 };
 79 
 80 //-- int, double ---------------------------------------------------------------
 81 template <>
 82 struct Promotion<intdouble>
 83 {
 84     typedef double  Type;
 85 };
 86 
 87 template <>
 88 struct Promotion<doubleint>
 89 {
 90     typedef double  Type;
 91 };
 92 
 93 //-- long, double ---------------------------------------------------------------
 94 template <>
 95 struct Promotion<longdouble>
 96 {
 97     typedef double  Type;
 98 };
 99 
100 template <>
101 struct Promotion<doublelong>
102 {
103     typedef double  Type;
104 };
105 
106 // namespace flens
107 
108 #endif // FLENS_AUX_PROMOTION_H